The thermal expansion coefficient of 3A21 aluminum plate and 3A21 aluminum plate aluminum alloy is about twice that of carbon steel and high alloy steel. The volume shrinkage rate of the 3A21 aluminum plate is relatively large when it condenses, and the deformation and internal stress of the welded parts are relatively large.
3A21 aluminum plate is an Al-Mn series alloy. 3A21 aluminum plate is the most widely used anti-rust aluminum. Its strength is not high (only slightly higher than industrial pure aluminum) and cannot be strengthened by heat treatment.