Method for improving phosphating performance of low-carbon aluminum killed steel automobile plate and automobile plate

Abstract

The invention particularly relates to a method for improving the phosphating performance of a low-carbon aluminum killed steel automobile plate and the automobile plate, and relates to the field of steel smelting. The method for improving the phosphating performance of the low-carbon aluminum killed steel automobile plate comprises the steps of casting blank component control, hot rolling, cold rolling, annealing and leveling; in the casting blank component control step, casting blank are controlled to comprise the following components of, in percentage by mass, 0.01% to 0.02% of C, smaller than or equal to 0.02% of Si, 0.10% to 0.30% of Mn, smaller than or equal to 0.015% of P, smaller than or equal to 0.015% of S, 0.03% to 0.06% of Al, 0.001% to 0.003% of B, smaller than or equal to 0.005% of N and the balance Fe and inevitable impurities; in the hot rolling step, the tapping billet temperature is 1140 DEG C to 1240 DEG C, the rough rolling outlet temperature is 1020 DEG C to 1100 DEG C, the final rolling temperature is 900 DEG C to 960 DEG C; in the cold rolling step, the cold rolling reduction rate is 67.6% to 86.1%; and in the annealing step, the dew point temperature of a heating section of an annealing furnace is-30 DEG C to 0 DEG C. According to the embodiment of the method for improving the phosphating performance of the low-carbon aluminum killed steel automobile plate and the automobile plate, the low-carbon aluminum killed steel automobile has the advantages that the grain size of a phosphating film on the surface is less than 5 microns, the coverage rate is 100%, the P ratio is more than 85%, and the phosphating performance is excellent.

Description

technical field

[0001] The invention relates to the field of steel smelting, in particular to a method for improving the phosphating performance of a low-carbon aluminum-killed steel automobile plate and the automobile plate. Background technique

[0002] Phosphating is a process in which chemical and electrochemical reactions form a phosphate chemical conversion film, and the formed phosphate conversion film is called a phosphating film. The purpose of phosphating mainly includes the following aspects: 1) Provide protection to the base metal and prevent the metal from being corroded to a certain extent; 2) It is used as a primer before painting to improve the adhesion and corrosion resistance of the paint film layer; 3 ) is used for anti-friction lubrication in metal cold working process.

[0003] At present, the low-carbon aluminum-killed steel automobile sheet has the problem of insufficient phosphating performance. Contents of the invention

[0004] In view of the ab...

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