What’s Impact on Chinese Aluminum Producers from New Environmental Drive?

The second round of 7 environmental protection inspection teams arrived in seven regions from November 24 to 30 to supervise environmental protection work, including Beijing, Shanghai, Guangdong, Hubei, Chongqing, Shaanxi and Gansu.
What’s impact on producers in the aluminum industry from the inspections?

Aluminum and alumina producers

Chinese government has taken a tough stance in environmental protection inspections since the beginning of 2016. Domestic aluminum and alumina producers are mostly large-size producers equipped with environmental protection facilities, and so they have suffered little impact from the inspections, except one aluminum producer in central China. The producer was requested to shut down its captive power plant and to source electricity from power plant directly in the previous round of inspections.

SMM survey finds that one alumina producer in Chongqing has been requested to cut alumina capacity by 350,000 tonnes for environmental upgrading after excessive discharge of pollutants. The producer is now running at 350,000-tonne alumina capacities, with output all for its aluminum production use. So far, it is unknown for offline capacities to go back to normal.

Aluminum processing producers 

Domestic aluminum processing producers are suffering a big impact from environmental protection inspections, SMM survey finds. The stricter inspections led to closures of aluminum billet producers in Inn Mongolia’s Huolinhe, switching from coal to natural gas at copper plate/strip, sheet and foil producers in Gongyi, and production halts at small and medium coal-fired aluminum extrusion producers in Hebei.

In recent days, aluminum processing producers have been hit by the inspections in Foshan, Guangdong. This is not the first inspections on local producers in the region, and the local government has started inspections on aluminum extrusion producers since 2014. In accordance with Air Pollution Prevention and Control Action Plan on Aluminum Extrusion Producers in Foshan in 2014, the local government closed 37 producers in Nanhai District, and completed rectification work on 94 producers.

Since 2016, environmental protection inspection teams sent by China’s central government arrived in the region, and the local government stepped up efforts to push for the inspections. Foshan’s government this April introduced the Plan for Promoting Air Pollution Prevention and Control Action on Aluminum Extrusion Producers in 2016-2017. According to the plan, a new round of inspections would be carried on all 157 aluminum extrusion producers in the region, and all producers would be requested to complete clean energy upgrading before late June 2017, or they would be shut down. Currently, 51 producers in Nanhai have completed the upgrading, and another 75 producers will finish the overhaul by late October.

Some small and medium-size producers have closed their smelting furnaces for severe energy pollutions, shifting raw material from aluminum ingot to aluminum billet. Processing fees for aluminum billet, which has already been tight, skyrocketed in the region after the shift, and trading for aluminum ingot was sluggish as a result, reversing the gap between Guangdong and Shanghai.

SMM believes that the impact from environmental protection inspections will be a typical regional one, and will be limited on the overall industrial chain. Hence, the impact on price will be small in all price influential factors. Attention should be paid more to whether or not producers violating the rules will upgrade their units to meet requirements, so as to give more consideration to environment and future generations than costs and profits.

Chinese output hikes could cap aluminum’s further climb

TOKYO — Aluminum’s worldwide rally could be near its end as China boosts exports of the metal not needed at home amid the nation’s massive production capacity.

Charting the rise

Three-month aluminum futures on the London Metal Exchange traded around $1,760 per ton Monday night, Japan time — about 10% higher than during a recent low Oct. 20.

An upswing in the Chinese futures market led this increase. Prices for steel materials such as iron ore and coal have been climbing for some time in China. Speculators are now racing to close short positions in aluminum as well, anticipating greater Chinese infrastructure investment and construction demand.

“Funds are flowing into nonferrous metals from the overheating real estate market,” among other sectors, said Shinya Ikezaki, chief trader at Japanese trading house Mitsui & Co.’s LME department.

Hopes also are high for aluminum demand in the U.S., as President-elect Donald Trump has promised massive infrastructure investment. In addition, American automakers have been developing pickup trucks using lightweight aluminum alloys since last year to help meet tougher fuel-efficiency standards.

‘Crumbling’ relationship

But a closer look at China, the world’s leading aluminum producer and consumer, shows dimmer prospects for the market overall. The strength of the nonferrous metals market and the country’s rapidly growing gross domestic product have been tightly correlated over the past 20 years. However, this relationship “is crumbling,” said Takayuki Homma of Sumitomo Corp. Global Research.

This change could be linked to an overexpansion in production capacity as well as a surge in real production, particularly in aluminum. Sources such as the Japan Aluminium Association estimate global output of the metal exceeds 50 million tons annually. China accounted for 30.8 million tons of output in 2015. Yet aluminum production capacity in that country is thought to have crossed 40 million tons in the past five years, according to an official handling bullion at trading house Marubeni.

The global market is paying the price for this capacity boom. China produces more aluminum than can be consumed domestically, and the country exports to destinations such as the U.S., Europe and Southeast Asia in the form of aluminum products to avoid import tariffs. In 2015, China sent a record 4.76 million tons of aluminum overseas, including bullion, alloys and more processed products. Exports totaled 3.82 million tons in the first 10 months of 2016, and recent weakness in the yuan could fuel further shipments.

China’s aluminum refineries now operate at roughly 75% capacity on average. Output likely will climb with prices. Even if China’s economic recovery stokes domestic demand and speculators’ forays into the futures market continue, it is difficult to imagine that the London Metal Exchange three-month price of the metal will cross into the $1,900 level in the near future, market sources say.

China’s Oct 21-30 aluminum price rises 6% from Oct 10-20

China’s domestic primary aluminum price averaged Yuan 14,232.10/mt ($2,105/mt) over October 21-30, up 6.3% from October 11-20, the National Bureau of Statistics said in a report Friday.

NBS conducts a survey on domestic prices, covering nine categories of essential feedstocks, three times a month.

Aluminum falls under the category of nonferrous metals. This category also includes the prices of copper, lead and zinc ingot.

The average price of copper was Yuan 38,025.90/mt over October 21-30, up 0.9% from the previous period; lead was up 3.1% at Yuan 16,017.10/mt and zinc down 3.9% at Yuan 18,844.90/mt.

What does ‘mill finish’ of aluminum mean?

“Mill Finish” is the natural appearance of the aluminum as it comes from the rolling mill or the extrusion mill. It is “as is” with no external mechanical or chemical finishing. Extruded metal is considered “mill finish”. All aluminum has an oxide of some varying thickness. Anodizing is a very heavy controlled oxide. Anodizing is an electrolytically formed and controlled heavy oxide 0.0003 inches thick on up the 0.002 and on up. Mill Finish is a very lightly oxidized film and will wipe off with your bare finger and immediately form. Rolled sheet would probably have a thinner oxide than hot extruded aluminum. If you want to bond silicone adhesive then you want a phosphate etch, or a light chromate or a thin (.0004 anodize in either chromic, sulfuric, or phosphoric.) If you anodize, do not seal the coating and be sure your anodizer knows you do not want it sealed.

Things You Should Know About Chinese New Year

year-of-the-monkey-2016The 2016 Chinese Lunar New Year will be on Feb. 8 and it is the year of the Monkey. Think Christmas but the date varies based on the lunar calendar, however, it normally falls between mid-Jan to end of Feb.

As important as the Chinese New Year is for those celebrating across Asia and around the world, it should also be significantly important for importers and those working with Chinese manufacturers. The Chinese New Year basically shuts down all production facilities throughout the country and it’s usually much more than a 3-day weekend.

Experienced importers are usually well aware of this time and the delay they can expect for shipments coming out of China around this time. The time is especially crucial for those that have businesses selling seasonal merchandise such as apparel and sporting goods. Failing to implement proper precautions during the Chinese New Year can result in heavy losses for businesses. And the variable date is one of the factors that can usually lead to confusion and planning complexities.

So what do you need to know as we approach the year of the Monkey?

  1. Usually all production and sample development is halted a week to 2 weeks prior to Chinese New Years Eve.
    It’s hard to put it in perspective if you haven’t been in China during this time. Majority of factory workers are going back and forth to their hometowns, combined with families traveling around China to visit relatives.
  2. Production is usually suspended for at least 2 weeks after the Chinese New Year
    While the holiday itself lasts roughly 5 days, most people seize the opportunity and extend the holiday by an extra week or two. So you may not be able to reach someone for 2 weeks or more about your order during this time.
  3. Getting back to normal is sometimes a struggle
    Think about that first Monday after your 2-week long vacation. Well it’s similar in a way and many manufacturers do struggle to get back into normal mode, but they eventually do.

So to recap, the Chinese New Year can turn into a 2-3 week shutdown for most factories and it’s a time of the year where majority of the people in the country are traveling. As a good rule of thumb, importers should do their research on the holiday and proactively schedule their orders and deliveries well before everyone gets in vacation mode.

Also keep in mind that leading up to the Chinese New Year, your supplier is probably rushing to fulfill orders for most of their buyers and get them shipped before they post the ‘We’ll Be Back’ sign on their doors. It is on you as a buyer to ensure that proper quality control standards are met during this time by making sure you hire a local inspector to perform a pre or post manufacturing inspection.

Types of American Windows and Doors

Double-Hung Window
A double-hung window has two vertically sliding sash (glass panels) in a single frame. Double-hung windows lift open while remaining flush with the wall, making them ideal around patios, decks and walkways. Both top and bottom sash tilt in for easy cleaning.
  Single-Hung Window
This style is the same as a double-hung window in appearance, but only the bottom sash opens for ventilation.
  Casement Window
Casement windows are hinged windows that open outward to the right or to the left. They’re common above kitchen sinks and give you the flexibility to group them in stunning combinations.
  Gliding Window

These windows feature two or three sash, with at least one of the sash sliding past the others. They provide the advantages of double-hung windows with a more contemporary look.

  Awning Window
Awning windows are hinged at the top and open outward. They catch breezes from the left or right and are often used above, below or alongside stationary windows.
  Specialty Window
Specialty windows are stationary (nonopening) windows characterized by their special shapes, including curves and dramatic angles. They can make a signature statement in your home or provide a delicate lighting accent.
  Hopper Window
Hopper windows open inward from the top.  They’re an ideal choice for basements, garages and attics.  Hoppers are great for areas with limited space that need ventilation.
  Bay or Bow Window
Bay and bow windows are window combinations that project outward from a home.  These dramatic combinations can add space, volume and light to a room and add more personality to any home.
  Gliding Patio Door
Gliding patio doors have at least one door panel that glides smoothly past another panel. When space is at a premium, gliding patio doors offer a convenient way to access your patio without having to worry about interior furniture placement or possible exterior obstacles.

Effect of Aging on Formability of Aluminum Alloys

Formability or workability is generally defined as the amount of deformation that can be given to a specimen without fracture or necking in a given process. Workability is not an intrinsic material property; it depends on design variables:

  • process variables – stress, strain, strain rate, temperature, lubrication, etc., and
  • material variables – size, shape, and amount of second-phase particles, grain size, etc.

Therefore, for a given shape, workability is a function of material and process variables and can be expressed as

Workability = ƒ1 (material) -ƒ2 (process)
where ƒ1 is a measure of the ductility of the material under processing conditions, represented by forming limit criteria developed for various processes. Forming limit criteria based on limiting strains are of practical applicability because strains, as opposed to stresses, are easy to visualize and analyze in workability studies. The ƒ2 function, on the other hand, is given by stress, strain, strain-rate, and temperature histories at the potential failure sites of the work piece.

A complete workability analysis involves:

  • establishment of forming limit criteria (ƒ1) as a function of strain rate and temperature;
  • determination of stress, strain, strain-rate, and temperature histories (ƒ2) at potential failure sites; and
  • comparison of the results of flow analysis (ƒ2) with the forming limit criteria (ƒ1).

This comparison reveals the margin of safety for the deformation processing of a defect-free product. When a negative margin exists, it assists in deciding on the necessary changes in material or process variables, or both.

Free surfaces are the most commonly observed fracture sites in bulk deformation processes. In most cases, free-surface fractures determine the limits of deformation that can be imparted to the deforming material. Such fractures occur at the free surfaces of the specimen during processing, for example, edge cracking in rolling, surface cracking in bending, heading, open-die forging, or surface cracking before contact is achieved between the preform and the die walls in an impression-die forging.

There is developed a fracture criterion, based on limiting strains-to-fracture, for the prediction and prevention of surface cracks in bulk deformation processes. Local strains calculated from measurements, at fracture, of grid markings on the free surfaces of cylinders upset under different friction conditions and with different height-to-diameter ratios, are plotted. Fracture strains obtained from bend tests, measured by grid markings on convex surfaces of bend specimens, fall onto the extension of the fracture line determined by compression tests. Thus, bend tests are complimentary to compression tests, and are particularly useful when compression testing is not feasible.

The material function ƒ1, has not been studied systematically. Recently, has examined the effect of size, shape, and volume fraction of second-phase particles on the bulk formability of American Iron and Steel Institute (AISI) 1040, 1060, and 1090 carbon steels. The present study evaluates the workability of three heat-treatable aluminum alloys as influenced by aging and accompanying structural changes.

Three heat-treatable aluminum alloys (2014, 2024, and 7075) were received in the form of 12.7 mm diameter rods. The 2014 (≈100HB) and 2024 (≈130HB) aluminum alloys were in T4 condition. The 7075 alloy was received in T6 condition (≈150 HB).

Chemical compositions of aluminum alloys:

  • Aluminum alloy 2014: Cu-4.7%; Mg-0.5%; Mn-0.7%; Si-0.6%; Fe-0.3%
  • Aluminum alloy 2024: Cu-4.3%; Mg-1.5%; Mn-0.7%; Si-0.2%; Fe-0.3%
  • Aluminum alloy 7075: Cu-1.6%; Mg-2.5%; Mn-0.2%; Si-0.2%; Fe-0.3%; Zn-5.6%

The degree of banding in the 2014 aluminum alloy was more severe, and the elongated grains were larger near the surface. These large grains at the surface layers caused surface wrinkling during upset testing of the alloy, necessitating machining off a layer of 0.7 mm thickness from the surface in order to bring the wrinkling to an acceptable level. In the 2024 and 7075 aluminum alloys, surface wrinkling was minimal; the original surfaces were preserved during testing.

In order to study the effect of aging on workability, the alloys were solution treated (470-500°C) and aged to four different levels: naturally aged, peak-aged, over-aged, and highly over-aged. Solution treatments were carried out in a tube furnace in argon for the 2014 alloy, and in nitrogen for the 2024 and 7075 alloys. This was followed by quenching in an ice-water mixture.

Tests for the naturally aged condition were carried out after aging the specimens at room temperature (25°C) for one week. An oil bath was used for artificial aging. No recrystallization was detected after solution or aging treatments.

The 2024 aluminum alloy shows greater workability than the 2014 and 7075 alloys in all conditions. While the workability index in the 7075 alloy is improved ≈50 percent by over-aging, improvement in workability levels in the 2000 series is more pronounced. In these alloys, the workability index in the highly over-aged condition is approximately three times that of the naturally aged condition.

Upset test specimens of the 7075 alloy revealed exclusively 45-deg cracks in all conditions. The 2014 aluminum alloy specimens also showed 45-deg cracks, except in the highly overaged condition, where cracks in ≈20 percent of the specimens were vertical (also known as normal). These vertical cracks were randomly located on the fracture line.

In the 2024 alloy, both vertical and 45-deg cracks were observed in all conditions; in general, specimens with low aspect ratios tested under high friction conditions gave vertical cracks. The percentage of specimens containing vertical cracks increased with increased aging time. In the naturally aged condition, only ≈15 percent of the specimens had vertical cracks. This type of crack was seen in ≈20 percent in peak-hardness specimens and ≈50 percent of those in the over-aged conditions. In the highly over-aged condition, though, ≈90 percent of the specimens exhibited vertical cracks. It is clear that 45-deg cracking is the predominant fracture mode at low workability levels in this alloy.

The 45-deg cracks did not penetrate the cross-section of the specimens in the 2000 series alloys. Cracks in the 7075 alloy, however, generally traversed the cross-section of the specimen; there was no indication that cracking started in the center of the specimens.

In the three alloys, the poorest bulk workability was obtained in the naturally aged and peak-aged conditions, where the precipitated particles were small and sharable. Localization of shear in these conditions in heat-treatable aluminum alloys is well documented. Localization of shear and accompanying voiding in the 7000 series aluminum alloys has been studied and co-workers and Leroy and Embury.

Chung and co-workers observed the occurrence of localized shear failure in 7075-T4 aluminum alloy before the onset of necking and concluded that either deformation softening or negative strain-rate sensitivity was necessary for localization to occur. The degree of localization in overaged conditions, however, should be lower than that in the naturally aged condition, as evidenced by the small improvement in the workability level.

Results of tension and compression tests on 2014 alloy indicate that lack of shear localization in tension is not a guarantee that this phenomenon will be prevented in compression. In the compression of overaged specimens of this alloy, only 45-deg cracks are observed, and the persistence of localized shear failure is probable. It appears that the 2024 alloy is least affected by shear localization among the three alloys, as evidenced by the high degree of workability and occurrence of vertical cracks in all conditions.

Annealing of Aluminum and Aluminum Alloys

Work hardening is used extensively to produce strain-hardened tempers of the non-heat-treatable alloys. The severely cold worked or full-hard condition (H18 temper) is usually obtained with cold work equal to about 75% reduction in area. The H19 temper identifies products with substantially higher strengths and greater reductions in area. The H16, H14, and H12 tempers are obtained with lesser amounts of cold working, and they represent three-quarter-hard, half-hard, and quarter-hard conditions, respectively.

A combination of strain hardening and partial annealing is used to produce the H28, H26, H24, and H22 series of tempers; the products are strain hardened more than is required to achieve the desired properties and then are reduced in strength by partial annealing.

A series of strain-hardened and stabilized tempers – H38, H36, H34, and H32 – are employed for aluminum-magnesium alloys. In the strain-hardened condition, these alloys tend to age soften at room temperature. Therefore, they are usually heated at a low temperature to complete the age-softening process and to provide stable mechanical properties and improved working characteristics.

Products hardened by cold working can be restored to the O temper, a soft, ductile condition, by annealing. Annealing eliminates strain hardening, as well as the changes in structure that are the result of cold working.

The distorted, dislocated structure resulting from cold working of aluminum is less stable than the strain-free, annealed state, to which it tends to revert. In zone-refined aluminum, this reversion may take place at room temperature. Lower-purity aluminum and commercial aluminum alloys undergo these structural changes only with annealing at elevated temperatures. Accompanying the structural reversion are changes in the various properties affected by cold working. These changes occur in several stages, according to temperature or time, and have led to the concept of different annealing mechanisms or processes. The first of these, occurring at the lowest temperatures and shortest times of annealing, is known as the recovery process.

Recovery

Structural changes occurring during the recovery of polygonization and subgrain formation has been obtained by x-ray diffraction and confirmed with the electron microscope. The electron micrographs may show the change in structure that accompanies advanced recovery. The reduction in the number of dislocations is greatest at the center of the grain fragments, producing a subgrain structure with networks or groups of dislocations at the subgrain boundaries. With increasing time and temperature of heating, polygonization becomes more nearly perfect and the subgrain size gradually increases. In this stage, many of the subgrains appear to have boundaries that are free of dislocation tangles and concentrations.

The decrease in dislocation density caused by recovery-type annealing produces a decrease in strength and other property changes. The effects on the tensile properties of 1100 alloy are shown in Fig. 1. At temperatures through 450°F (230°C), softening is by a recovery mechanism. It is characterized by an initial rapid decrease in strength and a slow, asymptotic approach to a strength that is lower, the higher the temperature.

fig1391
Fig. 1. Isothermal annealing curves for 1100-H18 sheet.
Recovery annealing is also accompanied by changes in other properties of cold worked aluminum. Generally, some property change can be detected at temperatures as low as 200 to 250°F (90°C to 120°C); the change increases in magnitude with increasing temperature. Complete recovery from the effects of cold working is obtained only with recrystallization.

Recrystallization

Recrystallization is characterized by the gradual formation and appearance of a microscopically resolvable grain structure. The new structure is largely strain-free. There are few if any dislocations within the grains and no concentrations at the grain boundaries. Recrystallization occurs with longer times or higher heating temperatures than do the recovery effects described in the preceding section, although some overlapping of the two processes is usual.

Recrystallization depends upon time and temperature. This relationship can be expressed by a rate equation of the type:

1/t = ke-a/T

where t is time, T is the absolute temperature, e is the base of natural logarithms, and k and a are constants.

The constant a is frequently replaced by Q/R, where R is the gas constant and Q is an energy term, similar to an activation energy. Aluminum alloys generally show good agreement with this time-temperature relationship except when secondary reactions interfere, such as the solution or precipitation of intermetallic phases at annealing temperatures.

Composition also influences the recrystallization process. This is particularly true when various elements are added to extreme purity aluminum; almost any added impurity or alloying element will raise the recrystallization temperature substantially. For commercial-purity aluminum and commercial alloys, however, normal variations in composition have little effect on recrystallization behavior. Extensively cold worked commercial alloys usually can be recrystallized by heating for several hours at 650 to 775°F (340 to 410°C).

Grain size is also strongly affected by composition. Generally, common alloying elements and impurities such as Cu, Fe, Mg, and Mn decrease grain size. The effects of elements of limited solubility, such as Cr, Fe, and Mn, are influenced by the compounds they form with each other and with other elements, and by their distribution in the structure.

The recovery process is not accompanied by any significant change in preferred orientation or texture of the deformed metal. However, the new grains formed by recrystallization frequently develop in orientations that differ from the principal components of the deformation texture. This re-orientation has been extensively studied in rolled sheet and varies considerably with the past history and the composition of the alloy.

Recrystallization produces further changes in the properties of the deformed and recovered metal. These continue until annealing and recrystallization are complete. The properties then are those of the original, unstrained metal, except as they are changed by differences in grain size and preferred orientation. In heat treatable alloys, annealing also may be accompanied by precipitation and changes in solute concentration.

Recrystallization is also accompanied by a further decrease in stored energy, as measured calorimetrically, as well as by complete elimination of residual stresses.

Grain Growth After Recrystallization

Heating after recrystallization may produce grain coarsening. This can take one of several forms. The grain size may increase by a gradual and uniform coarsening of the microstructure. This is usually identified as “normal” grain growth.

It proceeds by the gradual elimination of small grains with unfavorable shapes or orientations relative to their immediate neighbors. This occurs readily in high-purity aluminum and its solid solution alloys, and can lead to relatively large, average grain sizes. Such grain growth is promoted by small recrystallized grains, high temperatures, and extensive heating. Some grain coarsening of this type also occurs in commercial aluminum alloys, but it is greatly restricted by finely divided impurity phases and by intermetallic compounds of elements, such as manganese and chromium that slows down the process pin the grain boundaries, and prevent further movement. Generally, these grains grow only at very high temperatures and may attain diameters of several inches.

Apparently, the normal growth-inhibiting effects of elements such as iron, manganese, and chromium are lost or modified at high temperatures, through solution or through changes in particle size and shape. Because of the high temperatures, the few grains that first lose or overcome these restraints grow rapidly and consume other potential growth centers, and in this manner, a few grains of very large size are formed.

In most alloys, high temperatures alone are not the only cause for “giant grains”: A small primary grain size and well-developed annealing texture are other factors that promote this form of grain growth.

Training about the aluminium profiles for sliding/casement window/door

training

Training about the aluminium profiles for sliding window/door & casement window/door. How could we make the sliding or casement window & door perfect ? Not only depends on the surface&design. every measure of the detailed place is every important. So we not only just sell aluminium profiles & window/door. also provide professional advice for the projects.From the aluminium profiles to hardware &many other details. Different cases could help to understand clearly. Customers here at site, even they are not window&door maker, they just aluminium profiles distributor, could understand well and shown a good performance during todays’ training!