5052 aluminum alloy production process and quality inspection

Introduction to 5052 aluminum alloy

5052 aluminum alloy is a representative product of the 5000 series aluminum alloy. It has excellent performance and is also the most common among the 5000 series aluminum alloys.

5000 series aluminum alloy is an aluminum alloy with magnesium as the main alloy element. It is a non-heat treatable strengthened aluminum alloy. This series of alloys has a low density and higher strength than 1000 series and 3000 series aluminum alloys. It is a medium-to-high-strength aluminum alloy and has good formability, corrosion resistance, weldability and fatigue resistance.

Among them, the representative and widely used 5052 aluminum alloy is mainly used to manufacture aircraft fuel tanks, oil pipes, sheet metal parts of transportation vehicles and ships, instruments, street lamp brackets and rivets, hardware products, rear projection TVs and other electrical appliance casings. This article mainly takes 5052 alloy as an example to conduct analysis and research on cold rolling, annealing and user usage.

5052 aluminum alloy production process

Selection of raw materials

The raw materials are 99.7% pure aluminum ingots, and corresponding alloy elements are added to make 5052 alloy large flat ingots, which are then trial-rolled by a 1450mm double-coiling hot rolling mill, and finally rolled into hot-rolled coils with a size of: 7. Omm×1120mm.

Cold rolling process

7.0mm×1120mm×Cmm 5052 alloy aluminum coil is rolled in multiple passes on the 1850 six-fold irreversible cold rolling mill at a processing rate of about 30%. The rolled product thickness is 1.42mm, and is further trimmed on the 1850 recoiler. , and finally achieve industrial annealing to remove surface residual oil and ensure the performance of the final product.

5052 alloy has a high magnesium content, poor processing performance, hard material, and stronger work hardening than 1000 series and 3000 series aluminum alloys. During the rolling process, edge cracks are easy to expand, which may cause severe strip breakage and interrupt the rolling process. . In order to achieve stable continuous rolling, the roughness Ra of the rolling mill work roll is selected from 0.7 to 0.8um, and the surface is inspected pass by pass to ensure that the surface is good and there are no rolling marks.

Reroll trimmed edges

The trimming of the finished product is controlled according to the width of 1019mm without a sleeve. Due to the hard material, it is difficult to start rolling. The speed of the entire trimming process is controlled at 200m/min, and the tension is around 21000N. When the edge crusher crushes, some of the edges are broken. Adhesion phenomenon, the overall process is relatively stable, and the plate shape is good when observed at the online entrance.

When rerolling and trimming, in order to reduce the residual oil stains on the board surface when the two small rollers of the edge trimming machine are pressed down, which affects the annealing effect, when producing 5052 alloy, it is necessary to remove the small rollers on both sides.

Annealing

The finished product status requirement is H32. At this time, the tensile strength is 210~230Mpa and the elongation can reach 12~22%. To meet customer requirements, the industrial annealing metal temperature can be determined to be 290~300~C. Combined with the furnace loading volume and roll size, Considering the degreasing condition of the surface, further determine the annealing system.

Tension bending and plate cutting

The 5052 aluminum coil are straightened and cut into specifications of 1.42x1018x590ram, and are packaged and delivered in stacks. The end user conducts inspection and acceptance. The acceptance items focus on the thickness of different areas of the plate, the flatness of the final plate shape, and the surface quality.

Quality inspection of 5052 aluminum alloy

Thickness detection

The user selects the head sample and measures the thickness around the plate to further detect the uniformity of the overall thickness.

Shape detection

Flat shape detection is divided into flat shape detection after correction by the straightening machine and final stamping, riveting, and manual correction flat shape detection. Among them, the flat shape detection after correction is online detection, and the online detection platform at the beginning of stretch straightening, the operator performs slicing Measure to ensure final product quality.

Surface inspection

After the 5052 alloy hot-rolled coil is cold-rolled to the finished product, the overall surface structure is uniform and delicate. The user does not conduct further inspections on the surface roughness. According to the current roughness control, it can meet the user’s requirements. There are no scratches on the upper and lower surfaces of each plate. Defects such as scratches and roll marks that affect use; annealing oil spots on the surface of the plate are the focus of inspection by the user. Once the straightened slice is found, the finished product cannot be sent to the user.

Conclusion

• ① The thickness uniformity of the head and tail of the product needs to be further improved, especially the thickness uniformity has a great impact on the shape of the finished plate;
• ②The plate shape of the products produced by the 1850 cold rolling mill can basically meet the user requirements according to the current control method;
• ③The overall surface of the finished product is good, but there are occasional oil spots on the edges. It is necessary to further improve the oil control, annealing and degreasing processes;
• ④The finished product has good performance and can meet user requirements.