A kind of 1000mpa grade low-carbon hot-dip galvanized dual-phase steel and its preparation method

Abstract

The invention belongs to the technical field of steel for high-strength automobiles and particularly relates to 1000 MPa low-carbon hot-galvanized dual-phase steel and a preparation method thereof. The 1000 MPa low-carbon hot-galvanized dual-phase steel comprises, by weight, 0.05-0.10% of C, 0.20-0.60% of Si, 1.40-1.90% of Mn, 0.20-0.70% of Cr, 0.20-0.50% of Mo, 0.02-0.06% of Al, 0.020-0.050% of Ti, 0.010-0.040% of Nb, 0.0010-0.0030% of B, less than or equal to 0.015% of P, less than or equal to 0.005% of S, less than or equal to 0.006% of N, and the balance Fe and inevitable impurities. The 1000 MPa low-carbon hot-galvanized dual-phase steel has the high forming property and high welding property and the excellent galvanizing property and mechanical property. The 1000 MPa low-carbon hot-galvanized dual-phase steel is 630-700 MPa in yield strength, 1010-1050 MPa in tensile strength and 11-14% in elongation.

Description

technical field [0001] The invention belongs to the technical field of high-strength automobile steel, and in particular relates to a 1000MPa low-carbon hot-dip galvanized dual-phase steel and a preparation method thereof. Background technique [0002] With the development of automobile lightweight technology, it has become an inevitable trend for automobile steel to develop towards high-strength steel. Due to the characteristics of low yield strength, high tensile strength and excellent plasticity, dual-phase steel has become the preferred high-strength steel for automobiles, and its consumption is expected to exceed 70% of the advanced high-strength steel for automobiles. With the continuous release of domestic auto sheet production capacity, the competition in the high-strength steel market has become increasingly fierce. Low-cost, high-performance dual-phase steel has become the goal pursued by various companies and has attracted great attention. A domestic automobile f...

AI Technical Summary

Problems solved by technology

Although hot-dip galvanized dual-phase steel with excellent comprehensive mechanical properties and surface quality can be obtained through its chemical composition and preparation method, its high content of C and Mn makes its welding performance significantly reduced, and cannot meet the requirements of automobile factories. C≤0.10% ; At the same time, due to the high aluminum content, the production difficulty is obviously increased, especially the problem of high aluminum water plugging

[0005] To sum up, the existing invention mainly considers the mechanical properties of dual-phase steel unilaterally, and does not comprehensively consider factors such as formability, galvanizing performance, and welding performance.

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