Continuously annealed or hot galvanized cold rolled transformation induced plasticity steel plate and preparation method thereof

Abstract

The invention provides a continuously annealed or hot galvanized cold rolled transformation induced plasticity steel plate and a preparation method thereof. The steel plate comprises the following components: 0.1-0.5% of C, 0.2-2.0% of Al, 0.5-2.5% of Mn, 0.02-0.12% of P, not more than 0.02% of S, not more than 0.01% of N and the balance of Fe. The method comprises smelting, rolling and continuous annealing or hot galvanizing and is characterized in that the hot rolling heating temperature is 1100-1250 DEG C; the heat is preserved for 1-4 hours; the initial rolling temperature is 1100 DEG C; the finish rolling temperature is 750-900 DEG C; the coiling temperature is less than 700 DEG C; accumulated cold rolled reduction is 40-80%; the continuous annealing temperature is 700-(Ac3+50) DEG C; the heat is preserved for 30-360 seconds; the cooling rate is 10-150 DEG C / s; the aging temperature is 250-600 DEG C; the aging time is 30-1200 seconds; the steel plate is cooled to the room temperature at a rate of 5-100 DEG C / s; the hot galvanizing and annealing temperature is 700-(Ac3+50) DEG C; the heat is preserved for 30-360 seconds; the cooling rate is 10-150 DEG C / s; the steel plate is cooled to 400-500 DEG C and enters into a zinc pot after the heat is preserved for 10-300 seconds; the zinc pot temperature is 450-500 DEG C; the impregnation time is 1-10 seconds; the steel plate is cooled to the zinc liquid temperature to be galvanized; the impregnation temperature is 450-500 DEG C; and the impregnation time is 1-10 seconds. The steel plate has good strength, plasticity, forming property, welding property and galvanizing property and is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgical products, in particular to a continuous annealed or hot-dip galvanized cold-rolled phase-change-induced plastic steel plate and a preparation method thereof. Background technique [0002] As people's requirements for automobile safety, environmental protection, energy saving, and weight reduction continue to increase, the application of advanced high-strength steel in automobiles continues to increase. TRIP (Transformation Induced Plasticity) steel, as an important member of advanced high-strength steel, has attracted the general attention of major automobile manufacturers and steel companies because of its comprehensive properties such as high strength, high plasticity and high impact. [0003] At present, the composition systems of continuous annealed or hot-dip galvanized cold-rolled transformation-induced plasticity steel sheets mainly include C-Si-Mn series and C-Al-Mn se...

AI Technical Summary

Problems solved by technology

However, because Al element lacks the solid solution strengthening effect of Si element, the strength of TRIP steel is low

In order to solve the problem of strength, people increase the strength of the steel plate by adding alloy elements such as Cu, Ni, Nb, V, Ti, etc. This method certainly improves the strength of the steel plate, but increases the cost of the steel plate

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