Aluminum coil annealing process

Abstract

The invention discloses an aluminum coil annealing process. The aluminum coil annealing process comprises the following steps that S1, an aluminum coil is fed into an annealing furnace, and the annealing furnace is sealed; S2, a check air outlet of the annealing furnace is sealed, the annealing furnace is vacuumized through vacuum equipment, and vacuumizing is stopped after the absolute vacuum degree in the annealing furnace reaches 0.2 pa; S3, nitrogen is pumped into the annealing furnace continuously so that the relative vacuum degree in the annealing furnace can be greater than or equal to0; S4, the temperature in the annealing is increased to 300-390 DEG C and is held; S5, when the annealing time requirements are met, an annealing furnace water cooling system is started, and the temperature in the annealing is decreased to 150 DEG C or lower; S6, nitrogen with the temperature being no higher than 50 DEG C is pumped into the annealing furnace; and S7, after the temperature in the annealing furnace is lower than the temperature of the pumped nitrogen, the aluminum coil is taken out. Through the process, the effect that the thickness of an oxide film of the annealed aluminum coilis smaller than 50 A can be ensured.

Description

technical field [0001] The invention relates to the field of metal processing, in particular to an annealing process for aluminum coils. Background technique [0002] Aluminum coils are widely used in electronics, packaging, construction, machinery, etc. There are many aluminum coil manufacturers in my country, and the production technology has caught up with developed countries. Different series of aluminum coils have different properties and different application occasions. [0003] LNG ships are ocean-going liquefied natural gas carriers. The tank materials of LNG ships are usually Ni36 Invar alloy, 9% Ni steel and 5083 aluminum alloy. The liquefied natural gas in the tank of an LNG ship is at minus 162 degrees Celsius, and the tank needs to have sufficient strength and toughness. Therefore, when the material of the tank is 5083 aluminum alloy, the welding of the aluminum alloy requires extremely high requirements. , there can be no small uneven welding strength, but wh...

AI Technical Summary

Problems solved by technology

The liquefied natural gas in the tank of an LNG ship is at minus 162 degrees Celsius, and the tank needs to have sufficient strength and toughness. Therefore, when the material of the tank is 5083 aluminum alloy, the welding of the aluminum alloy requires extremely high requirements. , there can be no small uneven welding strength, but when the aluminum coil is conventionally annealed, there will be a certain thickness of oxide film on the outer surface of the aluminum plate. After the thickness of the oxide film exceeds 50A, the strength of the weld after welding will be insufficient, so that The welded tank body does not meet the requirements for use