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http://aluminium.matter.org.uk/content/html/eng/default.asp?catid=214&pageid=2144417044

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With the growth of aluminum within the welding fabrication industry, and its acceptance as an excellent alternative to steel for many applications, there are increasing requirements for those involved with developing aluminum projects to become more familiar with this group of materials. To fully understand aluminum, it is advisable to start by becoming acquainted with the aluminum identification / designation system, the many aluminum alloys available and their characteristics.

The Aluminum Alloy Temper and Designation System

In North America, The Aluminum Association Inc. is responsible for the allocation and registration of aluminum alloys. Currently there are over 400 wrought aluminum and wrought aluminum alloys and over 200 aluminum alloys in the form of castings and ingots registered with the Aluminum Association. The alloy chemical composition limits for all of these registered alloys are contained in the Aluminum Association’s Teal Book entitled “International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys” and in their Pink Book entitled “Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot. These publications can be extremely useful to the welding engineer when developing welding procedures, and when the consideration of chemistry and its association with crack sensitivity is of importance. 

Aluminum alloys can be categorized into a number of groups based on the particular material’s characteristics such as its ability to respond to thermal and mechanical treatment and the primary alloying element added to the aluminum alloy. When we consider the numbering / identification system used for aluminum alloys, the above characteristics are identified. The wrought and cast aluminums have different systems of identification; the wrought having a 4-digit system, and the castings having a 3-digit and 1-decimal place system.

Wrought Alloy Designation System

We shall first consider the 4-digit wrought aluminum alloy identification system.

The first digit (Xxxx) indicates the principal alloying element, which has been added to the aluminum alloy and is often used to describe the aluminum alloy series, i.e., 1000 series, 2000 series, 3000 series, up to 8000 series (see table 1).

 

WROUGHT ALUMINUM ALLOY DESIGNATION SYSTEM

Alloy SeriesPrincipal Alloying Element
1xx99.000% Minimum Aluminum
2xxCopper
3xxManganese
4xxSilicon
5xxMagnesium
6xxMagnesium and Silicon
7xxZinc
8xxOther Elements

Table 1


The second single digit (xXxx), if different from 0, indicates a modification of the specific alloy, and the third and fourth digits (xxXX) are arbitrary numbers given to identify a specific alloy in the series. Example: In alloy 5183, the number 5 indicates that it is of the magnesium alloy series, the 1 indicates that it is the 1st modification to the original alloy 5083, and the 83 identifies it in the 5xxx series.

The only exception to this alloy numbering system is with the 1xxx series aluminum alloys (pure aluminums) in which case, the last 2 digits provide the minimum aluminum percentage above 99%, i.e., Alloy 1350 (99.50% minimum aluminum).

Cast Alloy Designation

The cast alloy designation system is based on a 3 digit-plus decimal designation xxx.x (i.e. 356.0). The first digit (Xxx.x) indicates the principal alloying element, which has been added to the aluminum alloy (see table 2).

 

CAST ALUMINUM ALLOY DESIGNATION SYSTEM

Alloy SeriesPrincipal Alloying Element
1xx.x99.000% minimum Aluminum
2xx.xCopper
3xx.xSilicon Plus Copper and/or Magnesium
4xx.xSilicon
5xx.xMagnesium
6xx.xUnused Series
7xx.xZinc
8xx.xTin
9xx.xOther Elements

Table 2


The second and third digits (xXX.x) are arbitrary numbers given to identify a specific alloy in the series. The number following the decimal point indicates whether the alloy is a casting (.0) or an ingot (.1 or .2). A capital letter prefix indicates a modification to a specific alloy.

Example: Alloy - A356.0 the capital A (Axxx.x) indicates a modification of alloy 356.0. The number 3 (A3xx.x) indicates that it is of the silicon plus copper and/or magnesium series. The 56 (Ax56.0) identifies the alloy within the 3xx.x series, and the .0 (Axxx.0) indicates that it is a final shape casting and not an ingot.

The Aluminum Temper Designation System

If we consider the different series of aluminum alloys, we will see that there are considerable differences in their characteristics and consequent application. The first point to recognize, after understanding the identification system, is that there are two distinctly different types of aluminum within the series mentioned above. These are the Heat Treatable Aluminum alloys (those which can gain strength through the addition of heat) and the Non-Heat Treatable Aluminum alloys. This distinction is particularly important when considering the affects of arc welding on these two types of materials.

The 1xxx, 3xxx, and 5xxx series wrought aluminum alloys are non-heat treatable and are strain hardenable only. The 2xxx, 6xxx, and 7xxx series wrought aluminum alloys are heat treatable and the 4xxx series consist of both heat treatable and non-heat treatable alloys. The 2xx.x, 3xx.x, 4xx.x and 7xx.x series cast alloys are heat treatable. Strain hardening is not generally applied to castings.

The heat treatable alloys acquire their optimum mechanical properties through a process of thermal treatment, the most common thermal treatments being Solution Heat Treatment and Artificial Aging. Solution Heat Treatment is the process of heating the alloy to an elevated temperature (around 990 Deg. F) in order to put the alloying elements or compounds into solution. This is followed by quenching, usually in water, to produce a supersaturated solution at room temperature. Solution heat treatment is usually followed by aging. Aging is the precipitation of a portion of the elements or compounds from a supersaturated solution in order to yield desirable properties. The aging process is divided into two types: aging at room temperature, which is termed natural aging, and aging at elevated temperatures termed artificial aging. Artificial aging temperatures are typically about 320 Deg. F. Many heat treatable aluminum alloys are used for welding fabrication in their solution heat treated and artificially aged condition. 

The non-heat treatable alloys acquire their optimum mechanical properties through Strain Hardening. Strain hardening is the method of increasing strength through the application of cold working. The Temper Designation System addresses the material conditions called tempers. The Temper Designation System is an extension of the alloy numbering system and consists of a series of letters and numbers which follow the alloy designation number and are connected by a hyphen. Examples: 6061-T6, 6063-T4, 5052-H32, 5083-H112.

 

THE BASIC TEMPER DESIGNATIONS

LetterMeaning
FAs fabricated – Applies to products of a forming process in which no special control over thermal or strain hardening conditions is employed
OAnnealed – Applies to product which has been heated to produce the lowest strength condition to improve ductility and dimensional stability
HStrain Hardened – Applies to products which are strengthened through cold-working. The strain hardening may be followed by supplementary thermal treatment, which produces some reduction in strength. The “H” is always followed by two or more digits (see table 4)
WSolution Heat-Treated – An unstable temper applicable only to alloys which age spontaneously at room temperature after solution heat-treatment
TThermally Treated - To produce stable tempers other than F, O, or H. Applies to product which has been heat-treated, sometimes with supplementary strain-hardening, to produce a stable temper. The “T” is always followed by one or more digits (see table 5)

 Table 3


Further to the basic temper designation, there are two subdivision categories, one addressing the “H” Temper – Strain Hardening, and the other addressing the “T” Temper – Thermally Treated designation.

Table 4 - Subdivisions of H Temper – Strain Hardened

The first digit after the H indicates a basic operation:

H1 – Strain Hardened Only.

H2 – Strain Hardened and Partially Annealed.

H3 – Strain Hardened and Stabilized.

H4 – Strain Hardened and Lacquered or Painted.

The second digit after the H indicates the degree of strain hardening:

HX2 – Quarter Hard      HX4 – Half Hard      HX6 – Three-Quarters Hard

HX8 – Full Hard           HX9 – Extra Hard

                         

Table 5 - Subdivisions of T Temper – Thermally Treated

T1 - Naturally aged after cooling from an elevated temperature shaping process, such as extruding.

T2 - Cold worked after cooling from an elevated temperature shaping process and then naturally aged.

T3 - Solution heat treated, cold worked and naturally aged.

T4 - Solution heat treated and naturally aged.

T5 - Artificially aged after cooling from an elevated temperature shaping process.

T6 - Solution heat treated and artificially aged.

T7 - Solution heat treated and stabilized (overaged).

T8 - Solution heat treated, cold worked and artificially aged.

T9 - Solution heat treated, artificially aged and cold worked.

T10 - Cold worked after cooling from an elevated temperature shaping process and then artificially aged.

Additional digits indicate stress relief.

Examples:

TX51 or TXX51 – Stress relieved by stretching.

TX52 or TXX52 – Stress relieved by compressing.

Aluminum Alloys And Their Characteristics

If we consider the seven series of wrought aluminum alloys, we will appreciate their differences and understand their applications and characteristics.

1xxx Series Alloys – (non-heat treatable – with ultimate tensile strength of 10 to 27 ksi) this series is often referred to as the pure aluminum series because it is required to have 99.0% minimum aluminum. They are weldable. However, because of their narrow melting range, they require certain considerations in order to produce acceptable welding procedures. When considered for fabrication, these alloys are selected primarily for their superior corrosion resistance such as in specialized chemical tanks and piping, or for their excellent electrical conductivity as in bus bar applications. These alloys have relatively poor mechanical properties and would seldom be considered for general structural applications. These base alloys are often welded with matching filler material or with 4xxx filler alloys dependent on application and performance requirements.

2xxx Series Alloys – (heat treatable– with ultimate tensile strength of 27 to 62 ksi) these are aluminum / copper alloys (copper additions ranging from 0.7 to 6.8%), and are high strength, high performance alloys that are often used for aerospace and aircraft applications. They have excellent strength over a wide range of temperature. Some of these alloys are considered non-weldable by the arc welding processes because of their susceptibility to hot cracking and stress corrosion cracking; however, others are arc welded very successfully with the correct welding procedures. These base materials are often welded with high strength 2xxx series filler alloys designed to match their performance, but can sometimes be welded with the 4xxx series fillers containing silicon or silicon and copper, dependent on the application and service requirements.

3xxx Series Alloys – (non-heat treatable – with ultimate tensile strength of 16 to 41 ksi) These are the aluminum / manganese alloys (manganese additions ranging from 0.05 to 1.8%) and are of moderate strength, have good corrosion resistance, good formability and are suited for use at elevated temperatures. One of their first uses was pots and pans, and they are the major component today for heat exchangers in vehicles and power plants. Their moderate strength, however, often precludes their consideration for structural applications. These base alloys are welded with 1xxx, 4xxx and 5xxx series filler alloys, dependent on their specific chemistry and particular application and service requirements.

4xxx Series Alloys – (heat treatable and non-heat treatable – with ultimate tensile strength of 25 to 55 ksi) These are the aluminum / silicon alloys (silicon additions ranging from 0.6 to 21.5%) and are the only series which contain both heat treatable and non-heat treatable alloys. Silicon, when added to aluminum, reduces its melting point and improves its fluidity when molten. These characteristics are desirable for filler materials used for both fusion welding and brazing. Consequently, this series of alloys is predominantly found as filler material. Silicon, independently in aluminum, is non-heat treatable; however, a number of these silicon alloys have been designed to have additions of magnesium or copper, which provides them with the ability to respond favorably to solution heat treatment. Typically, these heat treatable filler alloys are used only when a welded component is to be subjected to post weld thermal treatments.

5xxx Series Alloys – (non-heat treatable – with ultimate tensile strength of 18 to 51 ksi) These are the aluminum / magnesium alloys (magnesium additions ranging from 0.2 to 6.2%) and have the highest strength of the non-heat treatable alloys. In addition, this alloy series is readily weldable, and for these reasons they are used for a wide variety of applications such as shipbuilding, transportation, pressure vessels, bridges and buildings. The magnesium base alloys are often welded with filler alloys, which are selected after consideration of the magnesium content of the base material, and the application and service conditions of the welded component. Alloys in this series with more than 3.0% magnesium are not recommended for elevated temperature service above 150 deg F because of their potential for sensitization and subsequent susceptibility to stress corrosion cracking. Base alloys with less than approximately 2.5% magnesium are often welded successfully with the 5xxx or 4xxx series filler alloys. The base alloy 5052 is generally recognized as the maximum magnesium content base alloy that can be welded with a 4xxx series filler alloy. Because of problems associated with eutectic melting and associated poor as-welded mechanical properties, it is not recommended to weld material in this alloy series, which contain higher amounts of magnesium with the 4xxx series fillers. The higher magnesium base materials are only welded with 5xxx filler alloys, which generally match the base alloy composition.

6XXX Series Alloys – (heat treatable – with ultimate tensile strength of 18 to 58 ksi) These are the aluminum / magnesium - silicon alloys (magnesium and silicon additions of around 1.0%) and are found widely throughout the welding fabrication industry, used predominantly in the form of extrusions, and incorporated in many structural components. The addition of magnesium and silicon to aluminum produces a compound of magnesium-silicide, which provides this material its ability to become solution heat treated for improved strength. These alloys are naturally solidification crack sensitive, and for this reason, they should not be arc welded autogenously (without filler material). The addition of adequate amounts of filler material during the arc welding process is essential in order to provide dilution of the base material, thereby preventing the hot cracking problem. They are welded with both 4xxx and 5xxx filler materials, dependent on the application and service requirements.

7XXX Series Alloys – (heat treatable – with ultimate tensile strength of 32 to 88 ksi) These are the aluminum / zinc alloys (zinc additions ranging from 0.8 to 12.0%) and comprise some of the highest strength aluminum alloys. These alloys are often used in high performance applications such as aircraft, aerospace, and competitive sporting equipment. Like the 2xxx series of alloys, this series incorporates alloys which are considered unsuitable candidates for arc welding, and others, which are often arc welded successfully. The commonly welded alloys in this series, such as 7005, are predominantly welded with the 5xxx series filler alloys.

Summary

Today’s aluminum alloys, together with their various tempers, comprise a wide and versatile range of manufacturing materials. For optimum product design and successful welding procedure development, it is important to understand the differences between the many alloys available and their various performance and weldability characteristics. When developing arc welding procedures for these different alloys, consideration must be given to the specific alloy being welded. It is often said that arc welding of aluminum is not difficult, “it’s just different”. I believe that an important part of understanding these differences is to become familiar with the various alloys, their characteristics, and their identification system.

Additional Information Sources

There are a number of excellent reference sources available exclusively addressing aluminum welding; One being the Aluminum Association’s “Welding Aluminum Theory and Practice” and another, is the American Welding Society Document D1.2 – Structural Welding Code – Aluminum. Other documents available from the Aluminum Association that assist with the design of aluminum structures are the Aluminum Design Manual and Aluminum Standards and Data. These documents along with the alloy designation documents mentioned earlier in the article can be obtained directly from the AWS, or The Aluminum Association as appropriate.


http://www.esabna.com/us/en/education/blog/understanding-the-aluminum-alloy-designation-system.cfm

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Premiums paid to secure aluminum are poised to exceed $500 a metric ton as soon as the coming quarter on stronger demand and limited supplies, according to United Co. Rusal (486), implying a jump of at least 20 percent.


At least 75 percent of stockpiles in London Metal Exchange warehouses are tied into financing transactions and unavailable for immediate withdrawal, Deputy Chief Executive Officer Oleg Mukhamedshin said today in a telephone interview from Moscow, where the company is based. The “overall” global surcharge, added to the price on the LME, will be “well above” $500 a ton in the third quarter, he said.


Buyers in Japan, Europe and the U.S. are paying record premiums for supplies of the lightweight metal. Stockpiles tracked by the LME fell in 19 of 20 sessions as of today to the lowest since May 2013. Aluminum for delivery in three months rose 2.5 percent this year to $1,846 a ton on the LME. A $500 premium would make up about 21 percent of total buying costs.


“There is quite a deficit in the spot market,” Mukhamedshin said. Surging premiums “should be a concern for the consumers who need to hedge.”


Buyers in Japan, Asia’s largest importer, agreed to pay a record premium for this quarter at $400 a ton. Spot premiums in Europe gained 47 percent this year to $412.50 a ton, including the European Union import duty, while the U.S. surcharge jumped 61 percent to 18.9 cents a pound ($417 a ton), according to Metal Bulletin data.


‘Strong Demand’


Aluminum usage outside China will exceed production by 1.3 million to 1.4 million tons this year on “quite strong demand,” Mukhamedshin said. Producers outside the Asian nation reduced output by about 3 million tons since 2012 and should cut a further 1.6 million tons this year, he said.


The market in China, the biggest producer and consumer of the metal, should be balanced as local output falls further, according to Rusal. The nation’s producers are losing money at current prices and output is set to slow as banks cut credit to loss-making companies, Mukhamedshin said.


Financing transactions, involving a simultaneous purchase of nearby metal and forward sale, are intended to capitalize on a market in contango, when prices rise for later deliveries. Changes in borrowing costs and storage fees affect the accords’ profitability. Aluminum for immediate delivery on the LME settled today at a $22-a-ton discount to the three-month contract, the narrowest gap since December 2012, according to data compiled by Bloomberg. That compares with $45 on Jan. 2.


Off-Warrant


“The contango is OK and interest rates are still low, so financial transactions are still profitable and the stock which goes off-warrant is still not available,” Mukhamedshin said, referring to supplies held outside the LME’s network. “This is exactly why the premiums are going up, and we expect more record-high premiums in the third quarter, well above $500 per ton.”

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By Andy Home

(Reuters) - Another quarter and another record premium level for Japanese aluminium buyers.


The premium over the London Metal Exchange cash price for third-quarter shipments to Asia's largest importer seems to be settling around the $400 per tonne level, up from $365-370 in the current quarter.


A year ago the premium PREM-ALUM-JP was just $250 and until the third quarter of 2012, it had never been higher than $130.


Japanese buyers, however, have little choice but to take the premium pain.


Although still viewed as a benchmark for the whole of Asia, the Japanese quarterly premium no longer has anything to do with regional supply-demand nuances. It is now just one manifestation of a global premium structure.


If Japanese buyers baulk, producers can simply point to premiums in North America and Europe with the implicit threat of diverting shipments to those markets.




THE UNSTOPPABLE PREMIUM MACHINE


That, certainly, is the stark warning from Oleg Mukhamedshin, Deputy Chief Executive of Russian aluminium giant Rusal, speaking to reporters earlier this week.


"We think the premium can easily reach a new record high well above $500," he said, adding for extra emphasis: "In the third quarter we can see new records, even $600 would not be out of the question."


What once would have seemed a flight of producer fantasy doesn't seem quite so far-fetched these days. Those who have tried to stand in the way of rising physical premiums have been steam-rollered - witness the short-covering frenzy that sent U.S. Midwest premiums into supernova at the start of this year.


The U.S. Midwest premium, as assessed by Platts, a leading global energy, metals and petrochemicals information provider, surged to an all-time high of 20.75 cents per lb ($457.45 per tonne) in early January. The pull-back made it only as far as 18.25 cents in early April and now the premium's rising again, hitting 19 cents at the end of May.


The same is happening in Europe and the unstoppable premium machine has just struck Japan.


So just how high might premiums go? To answer that question would mean disentangling the various interconnected drivers.


That is itself a major problem since there is no clear-cut consensus as to which of them holds the key to unlocking the premium riddle, a dilemma that was laid bare in the aluminium industry's fractured response to the LME's consultation on its warehousing policy.


Is it the load-out queues at LME locations such as Detroit and Vlissingen? Is it the in-vogue stocks-financing trade that has tied up so much surplus metal and kept it away from manufacturing users? Or is it the multiplying smelter closures that are pushing the market into deficit?


All are somehow in the mix and right now there's still no easy way of saying which is the most important.



ALL ABOUT QUEUES?


Take those infamous load-out queues, for example.


The LME's proposed solution to its queue problem has already altered warehouse company behaviour even though its load-in-load-out formula is stuck in legal limbo thanks to the courtroom fisticuffs between the exchange and Rusal.


The revolving door strategy employed by Metro in Detroit, whereby rental from the load-out queue financed incentives to attract more metal into its sheds, has been stopped. Not one tonne of aluminium has been warranted in Motown in the last two months.


The load-out queue, however, has still been growing because metal is still being cancelled and joining the queue, 180,000 tonnes of it over the course of April and May.


As of the end of April, the aluminium queue at Detroit stood at 683 days. The cost of getting metal out, a combination of the daily rental and the load-out charge, was $388 per tonne, within a whisker of Platts' then Midwest premium assessment of $406.


Until the queue actually starts shortening, the apparent linkage between the two remains intact. On current trends, the day is fast approaching since there are now only 158,525 tonnes of non-cancelled aluminium in the city.


But then there is Vlissingen, the Dutch port dominated by Pacorini, the warehousing arm of Glencore. Although inflows have slowed, they have by no means stopped and it looks like movement is being carefully calibrated to minimise queue decay in the event the LME's new policy makes it through the courts.


The aluminium queue here was 748 days at the end of April and the notional "value" was $406 per tonne. For those, and they are many, who argue that physical premiums are all about queues, there's nothing here to prove them wrong yet, although things will get a lot more interesting when the Detroit queue starts contracting.



FUNDS AND FUNDAMENTALS


But it should be clear by now that queues are not the only driver of premiums. After all, if less metal is flowing into the LME warehouse system and more leaving, why hasn't there been an impact on physical market availability and therefore premiums?


The answer comes in two parts.


Firstly, hardly any of that metal leaving Detroit and Vlissingen every day is going anywhere near an actual manufacturer. Rather, it is still mainly, and quite possibly totally, going to cheaper off-market storage to earn a tidy profit for stocks financiers.


The trade remains in robust good health. True, there has been a sharp contraction in the front part of the LME forward curve over the last couple of days, the benchmark cash-to-three-month period CMAL0-3 closing Wednesday valued at $22.25 contango, compared with over $40 a week ago. But we've seen these spread spasms come and go over recent years with little impact on the bigger financing picture.


And although the prospect of higher interest rates is looming larger in the United States and the UK, the European Central Bank has just moved in the opposite direction with a further loosening of monetary policy. As long as money remains cheap and interest rates low, one of the pillars of stocks-financing profitability remains firmly in place.


Then, of course, there is the fact that there is less metal around to plug the supply gap left by the financiers. As more and more smelter capacity is mothballed, this fundamental driver of higher premiums is assuming ever greater significance.


North American production was running at an annualised rate of 4.6 million tonnes in April, according to the latest figures from the International Aluminium Institute. That's the lowest level since August 2010.


Smelter capacity has been permanently lost in both western and eastern Europe over the last couple of years with many plants in the former still struggling to survive.


No-one sniggers any more when producers talk about a deficit market. What was once viewed as wishful thinking is rapidly becoming consensus.



HIGHER AND HIGHER?


To some extent it doesn't matter which of these drivers you think is the more important, since all three are still individually pushing premiums in the same direction.



For now at least.


At some stage it does look as if that Detroit queue is going to start contracting. And spread tightness could yet free up some of the aluminium locked up in financing deals, although the ironic net result may be to attract more metal into the LME system, where it can be snapped up again and placed back in load-out queues.


With so many moving parts, the aluminium premium machine may yet come unhinged but not in time to bail out Japanese buyers for their next quarter shipments.


And as for Rusal's claim that premiums could go higher still to $500 or "even $600" over the next few months? It still seems improbable. But it's by no means impossible. (Editing by David Evans)

http://www.reuters.com/article/2014/06/05/home-aluminium-idUSL6N0OM1XN20140605?rpc=401&feedType=RSS&feedName=rbssFinancialServicesAndRealEstateNews&rpc=401

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Aluminum-Sheet Use in Autos Seen Climbing Five-Fold

Global aluminum-sheet use in auto bodies will climb five-fold by 2020 as car manufacturers seek lightweight material to improve fuel economy, said Derek Prichett, a vice president of global recycling at Novelis Inc.


Sheet consumption will jump to 1.8 million metric tons from 350,000 tons currently, Prichett said in an interview in Chicago yesterday. Atlanta-based Novelis counts Ford Motor Co., Volkswagen AG’s Audi unit and the Jaguar Land Rover division of Tata Motors Ltd. as customers, according to its website.


A push in the U.S. and Europe to reduce carbon-dioxide emissions and increase mileage is prompting carmakers to seek to replace heavier materials such as steel. Ford begins production of an all-aluminum bodied F-150 pickup truck this year, and other car and truck manufacturers will follow suit, switching to aluminum over the next six years, Jack Clark, a senior vice president at Novelis, said in the same interview.


Aluminum content in light vehicles around the world, including bodies, hoods and doors, will rise to near 35 billion pounds by 2025, making the auto industry a “major” market for aluminum, Clark said.


Demand for the metal in North America will exceed production by 1.255 million metric tons in 2015, up from an estimated 1.13 million tons this year, partly because of increased shipments to the region’s auto industry, Jorge Vazquez, the managing director at researcher Harbor Aluminum Intelligence Unit LLC, said at a conference in Chicago yesterday.

Tighter Supply

The metal has risen 5.6 percent this year on the London Metal Exchange as supply tightens amid rising consumption and production cuts. The contract for delivery in three months fell 0.5 percent to $1,900.50 a ton on the LME yesterday.

Prices may near $2,000 a ton by mid-2015 after the market tips into a deficit in the second half of 2014, BNP Paribas SA said in a report May 8.

The trend in North America may spread to Japan, helping revive consumption of the metal in the transport sector, Takuki Murayama, the executive director of the Japan Aluminium Association, said in an interview in Chicago June 9.

To contact the reporter on this story: Luzi Ann Javier in New York at ljavier@bloomberg.net

To contact the editors responsible for this story: Millie Munshi at mmunshi@bloomberg.net Joe Richter

http://www.bloomberg.com/news/2014-06-11/aluminum-sheet-use-in-autos-seen-climbing-five-fold.html?

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Record offers for Q3 MJP premiums as talks continue

May 30, 2014 - 10:18 GMTLocation: Singapore

KEYWORDS: MJP , main Japanese premium , aluminium , deals , benchmark ,Rusal , Rio Tinto , Alcoa , BHP

The Japanese aluminium buyers are staring at record-high premiums of over $400 per tonne for third quarter delivery, with offers from major producers already above that level.

Three of the big four producers are offering premiums in the range of $405-410 per tonne, market participants have said. "We received $410 from Rio Tinto; from Alcoa the number is $408 and Rusal is offering $405. We have not received BHP's offer yet," a source at a large trading house in Japan said.  Second quarter Main Japan Port (MJP) premiums had settled at record-high levels of $365-369 per tonne.  Rio Tinto, which sent its offer letter on Tuesday May 27, attributed the increase to a tight market amid smelter shutdowns and high premiums in Europe...


http://www.metalbulletin.com/Article/3346913/Record-offers-for-Q3-MJP-premiums-as-talks-continue.html


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실리카겔의 단점
1. 염화코발트가 발암물질로 규정되어 유럽에서 사용금지품목으로 지정
2. 토지의 산성화를 시킴
3. 흡습율이 25%까지이나 온도가 60도 이상일 경우 반대로 습기를 내품는다
그래서 전자레인지에 열을 가하여 재생하여 쓸수가 있다고 하나 수출포장의 경우 적도를 지날 때 70도 이상의 기온을 감안하면 오히려 습기를 내품을 것은 자명하며 결로현상을 일으키고 이때 나우는 습기는 산성이므로 오히려 금속제품일 경우 발청을 촉진시키고 있다.

4. MSDS상 혼합금지 물질에 금속으로 표현되어 있는만큼 금속류의 포장에는 문제가 있는 제품이다.

실리카볼 (Silicaball V.C.I.)
실리카겔의 문제점을 완전히 해결함과 동시에 방청의 기능을 가진 방습제 천연광물질과 신소재 기화성방청재로 만든 흡습 방청제입니다.
인체에 전혀 무해한 크린제품입니다.


특징과 장점
1. 천연광물질과 생화학분해가 가능한 물질로 만들어진 친환경제품이다.
2. 기존의 실리카겔보다 2배이상의 흡습력과 동시에 방청기능을 보유함으로서 경제적효과가 높다.
3. 철 및 비철금속류 제품에 사용가능하며 포장부위나 프라스틱 고무 제품에 영향을 미치지 않는다.
4. 타 방청제가 침투하기 힘든곳이나 내부틈새를 포함한 금속념의 부식방지의 기능이 탁월하다.
적용분야
1. 각종 철 및 비철금속류의 기계나 원자재가 흡습의 기능을 요구할시
2. 수출포장시 방청지나 방청필름의 방청기능을 벗어난 공간이 있을시
사용방법
일반적인 환경하에서 100~200g/CBM이며 포장조건이나 환경에 따라 증감될수 있다(실리카겔 사용량의 1/3~1/2정도)
제품의 종류
부직포(10g,40g,50g,100g,500g)
물성
성상:암갈색을 띈 분말성알갱이
PH : Appx.6-7
부피비중:0.3~0.45g/cc
열안전성:400C이하
주의사항
보관시 직사광선을 피하고 밀폐된 용기에 40도 이하의 실내에서 보관
사용후 남은 제품은 밀봉후 보관한다.

Posted by shonini

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마대합지 



개요
마대포장지의 단점을 보완한 것이 마대 라미네이션이라면 마대 라미네이션을 보완 한 것이 마대합지이다. 중량물 포장에서 인장파열강도는 요구하고 포장내부의 공간을 크고 특히 철강재의 경우 온도차이에 따라 습기를 발산하는 성질이 있으므로 철강재 포장에 특히 적절하다.

특성
피포장물 내부에 습기가 잔존할 경우 이를 흡수할수 있게 크라프트지를 마대와 합지.
내부의 습기를 흡수할수 있는 크라프트지를 사용하였다. 경우에 따라서는 흡수력이 뛰어난 종이를 사용할수도 있다. 외부의 충격에 따라 마대의 강도를 높일수 있다.

적용분야 
철강포장재 기타 강도와 내부습기의 흡습을 원하는 포장

사용방법 및 주의사항 
환경적 측면이 강조되는 요즈음 재활용이 되지 않는 단점이 있다.

구성(재질) 
PP(PE)마대+ 크라프트지

형태 
마대포장의 사양과 동일.

비교 
마대포장지나 마대나미네이션등과 서로의 보완점과 단점을 비교 하여 피포장물의 환경과 가장 적절한 포장지를 선택해야 한다. 특히 크라프트지의 선택에 따라 흡습력을 배가 할수 있으므로 종이선택 또한 중요하다.

Posted by shonini

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아노다이징

Aluminum/BgInfo / 2014. 5. 26. 11:21

아노다이징의 정의 

 

금속(부품)을 양극에 걸고 희석-산의 액에서 전해하면, 양극에서 발생하는 산소에 의해서 소지금속과 대단한 밀착력을 갖인 산화피막(산화알미늄 : AlO)이 형성된다. 양극산화란 즉 양극 (Anode)과 산화 (Oxidizing)의 합성어(Ano-dizing) 이다.

전기도금에서 부품을 음극에 걸고 도금하는 것과는 차이가 있다.

양극산화의 가장 대표적인 소재는 AL이고 그 외에 Mg, Zn, Ti, Ta, Hf, Nb 의 금속 소재상에도 아노다이징 처리를 하고 있다. 최근에는 마그네슘과 티탄 소재상의 아노다이징 처리도 점차 그 용도가 늘어 가고 있다.

 

양극 산화 피막의 특성 

 

(1) 피막은 치밀한 산화물로 내식성이 우수하다. 

특히 시링 후 처리한 것은 일반의 대기 조건하에서나 염수분위기 하에서 내식성능이 대단히 우수하다. 아노다이징에 의해 생성된 비정질 (아몰포스 : Amorphous) 의 산화알미늄 피막을 약산성의 뜨거운 물이나 끓는 탈이온수 혹은 고온의 중크롬산나트륨액 혹은 아세트산니켈의 액에서 시링하면 최대의 내식성을 발휘한다.

(2) 장식성 외관을 개선한다 

모든 양극산화피막은 광택이 나고 상대적으로 우수적으로 모양을 내서 장식효과를 낸 다음에 아노다이징을 마지막 공정으로 사용하고 있다. 양극피막의 광택 수준은 처리전 금속소재의 조건의 좌우된다. 무광택 에칭은 광택을 줄이고 화학이나 전해연마, 버프연마 등은 광택을 낸다. 즉 소지의 확산이나 반사에 따라 광택이 다르게 된다. 건축용도로 사용하는 알미늄은 대부분 아노다이징으로 마감한다.

(3) 양극피막은 상당히 단단하여 내마모성이 우수하다. 

하드아노다이징(경질양극산화)는 두께가 25㎛~100㎛ 이상까지 두껍게 피막을 올릴 수 있다. 이들 피막은 산화알미늄의 고유경도로서 내마모성이 필요한 회전부품의 용도로 안성마춤이다. 모든 양극피막이 소재 재질보다 더 단단하지만 크롬산법이나 일부 황산법의 피막은 두께가 너무 엷고 물러서 내마모성에는 적합하지 않은 경우도 있다

(4) 도장밀착력의 향상 

단단히 밀착되어 있는 양극피막은 모든 페인트 시스템에서 화학적으로 활성표면을 제공한다. 황산욕에서 처리한 양극피막은 무색으로 다음의 투명한 표면처리에 하지로 적당하다. 가혹한 부식환경하에서 사용하는 알미늄 부품을 도장하는 경우에는 도장전에 아노다이징을 전처리로 처리한다. 시링한 것은 내식성이 더 좋고 시링을 하지 않은 것은 도장의 밀착력이 더 좋다

(5) 본딩성능의 개선 

인산법이나 크롬산법에 의한 엷은 양극피막은 본딩성과 내구성능을 개선한다. 이들 피막은 대부분의 최신 항공기의 기체구조에 넓게 이용하고 있다.

(6) 윤활성의 개선 

하드 아노다이징 후에 수동으로 연마나 혼닝으로 표면을 스므스하게 하고 그 위에 테프론 코팅을 하면 완벽한 윤활성능을 발휘할수 있다.

(7) 장식목적의 특유한 색상을 낸다 

양극피막의 다양한 착색은 몇몇 방법으로 처리한다. 유기염료를 피막의 기공속에 흡착시켜 다양한 색상으로 착색한다. 또한 일부 무기 안료는 기공에 침전치켜 제한된 범위의 안정한 색상을 만들 수 있다. 자연발색법의 아노다이징은 합금 조성에 따라 다르나 건축용도의 안정한 흙빛 색상의 착색에 적당하다. 전해착색은 2차공정으로 일반의 아노다이징 처리후에 2차로 피막의 기공에 금속 안료를 전기적으로 석출시켜 안정된 색상을 얻는다. 건축에 많이 이용하며 특히 샤시에 많이 활용하고 있다.

(8) 도금의 전처리 

일부의 양극피막은 고유의 다공성으로 전기도금을 할 수 있다. 일반적으로 도금전처리로 인산법 아노다이징을 처리한다.

(9)표면손상의 탐색 

미세한 표면크랙을 크롬산 아노다이징액을 사용하여 탐색할수 있다. 크롬산액에서 아노다이징 처리하고 수세후 빨리 건조하여 표면을 검사하면 부품에 금이 가 있는 경우에는 균열부위에 크롬산이 들어가서 이 부근에서 크롬산이 스며나와 양극피막을 오염시킨다.

 

아노다이징의 용도

 

알미늄과 알미늄하금 소재는 양극산화 피막처리에 널리 사용되고 있다. 애노다이징의 용도는 다음과 같다.

(1)
장식용 피막처리 (裝飾用 皮膜處理


장식고 방식목적으로 널리 사용한다. 전처리 조건이나 합금성분에 따라 광택, 반광택 혹은 무광택이 있고, 염색을 하여 다양하고 멋진 외관을 생산한다. 이에는 주로 황산법을 사용하며, 뽀얀 반투명이나 회색의 애나멜과 같은 외관을 원할때에는 크롬산법을 가끔 이용도 한다. 광학기기, 기계부품, 가전제품, 전기통신기기 등에 광범위한 용도를 갖고 있다.


(2)
건축용 애노다이징(建築用 陽極散花)
 

건물의 차아호, 도어, 커튼금구 등에 널리 사용한다. 사용환경이 자주 닦고, 옥외의 심한 환경에서 내후성이 우수하여야 하기대문에 피막의 두께가 두꺼워야 된다. 애노다이징 처리후 반시링을 하고 (전착)래커코팅을 하면, 보관이나 설치중에 피막의 손상을 방지하고, 젖은 시멘트와 내기후성에도 내성을 향상한다.

(3)
경질양극산화(Hard Anodizing : 硬質陽極散花


황산-수산의 혼산법도 있으나, 저온의 황산법이 대표적이다. 양극피막의 경도가 Hv 500정도로 실제 내마모성은 그 수치보다 더 우수하다. 전기 밥솥같은 가전부품, 화살대 같은 스포츠 용품, 방산제품, 기계부품 등에 널리 사용되고 있다.

(4)
내식목적의 피막처리 (耐蝕目的의 皮膜處理)
 

방산과 항공기 부품에 사용하고, 내식성이 주 목적일 때 가끔 크롬산법을 채용한다.

종류(TYPE)

코팅(산업용)등급

피막두께(최소)

A

공업용 경질 피막

30

B

건축용, 1

18

C

건축용, 2

10

D

자동차-외부

8

E

실내-중간정도 마모성

5.0

F

실내-한정된 마모성

3

G

크롬산

1


(5)
축전지(콘덴서) [蓄電池用

기공(Pore)이 없는 확산층의 양극산화 피막으로, 붕산법이 이에 속한다.
*
참고로 피막의 용도별 두께를 미국 ASTM B 580규격에서 인용하면 다음과 같다

※주기 : 경질피막은 두께가 12미크론부터 100미크론 이상까지 다양하다. 만일 A종의 경우 두께가 명시되어 있지 않으면, 최소 50미크론 이상이다. 만일 시링을 명시하지 않았다면, A종은 시링하지 아니한다

용도

양극산화처리의 종류

방식

황산법,옥살산법, 크롬산법, 기타유기산법

내마모

경질양극산화처리법(황산, 옥살산)

장식용

(전해연마, 화학연마) 황산법(염색)

광학용

(전해연마, 화학연마) 황산법(염색)

도장의 하지

황산법, 크롬산법

도금의 하지

인산법

건축용 ( 착색 )

자연발색법, 전해착색법

 

 

하드 아노다이징

 

A/L의 합금특성에 의한(저온 전해) H2SO4용액에 저온 전해 방법으로서 보통 양극산화 피막 보다는 내식성.내마모성.절연성이 있는 견고한 피막이며 적어도 30㎛이상이면 경질이라 말할 수 있다. 알미늄금속 표면을 전기.화학적 방법을 이용하여 알루미나 쎄라믹으로 변화시켜 주는 공법이다. 이공법을 적용하게 되면 알미늄금속 자체가 산화되어 알루미나 쎄라믹으로 변화되며 알미늄 표면의 성질을 철강보다 강하고 경질크롬도금보다 내마모성이 우수하다. 도금이나 도장(코팅)처럼 박리되지 않으며 변화된 알루미나 세라믹표면은 전기절연성(1500Volt)이 뛰어나며 안쪽은 전기가 잘흐른다. 이런 알미늄 금속에 하드-아노다이징(Hard-Anodizing) 표면처리 공법을 이용한 첨단기술이 개발,적용되고 있다.

)비행기표면,가벼워야하며 내마모성이 요구되는 산업기계,각종 산업시설의 슬라이드 부품, 롤러,반도체 장비등

분야별 구분

부품명

기계공업부품

베어링, 기어, 나사산, 소프로켓, 소형엔진용 피스톤, 노즐
롯기구, 샌드펌프, 볼트, 너트류

항공기부품

유압실린더 내면, 날개 끝, 하부 현수막, 케치, 헬리콥트 날개

방위산업체부품

실탄 케이스, 포신 포꼬질대, 장탄케이스

섬유방직부품

보빙기, 섹쇼날 빔, , 편직기 부품, 봉재기관계 부품

레져부품

낚시대 릴, 손잡이 링, 버너용 석쇠, 코펠, 자일, 텐트 지주대
카메라 장식부품

자동차부품

오일 실린더, 록커암, 브레이크 실린더 및 피스톤 부품
염분 및 내식성이 요구되는 부품, 항공기, 선박

기타

선박부품, 주방기물, 고무금형
인쇄기 로라, 자동경화 선멸기의 로라
엘르베이트 로라, 식품기계 가공품
복사기 용도기구 부품
컴퓨터 로라 및 드럼, AIR 실린더 호닝파이프
화작기계 부품(내산, 내알카리, 내하로겐)
가스터어빈(내열성, 도장기, 실린더 및 피스톤
각종 절연재료 부품

 

하드아노다이징의 특징


- 색상 자연발색 
-
고순도A/L~두께의 증가에 따라 은백색→황금색→갈색
-
합금~일반적으로 회색 또는 국방색, 흑색
- 7075
합 금~피막두께 25㎛ 백색, 25㎛이상~20㎛회색 암갈색, 200㎛이상 흑색

Posted by shonini

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구 분

중량계산법

합금비중

ALLOY

비중

SHEET

·두께(MM)×폭(M)×길이(M)×비중=중량(KG)

A1050
A1100
A3003
A3004
A3105
A5052
A5083

A5754

A8011

2.71
2.71
2.73
2.72
2.71
2.68
2.66
2.67
2.71

) A1050 T 1.2mm, W 1,212mm, L 2,424mm
:1.2
×1.212×2.424×2.71=9.55KG

COIL

·π{(R/2)2(M)-(r/2)2(M)}×폭(MM)×비중=중량(KG)
R :
외경 r:내경

) A1050 W 1000mm, OD 1200mm, ID305mm
:3.14
×{(1.2/2)2-(0.305/2)2}×1000×2.71=2865.49KG

 
 


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01-27 12:42