Super-high strength cold rolled steel belt suitable for rolling formation and manufacture method of super-high strength cold rolled steel belt

Abstract

The invention provide a super-high strength cold rolled steel belt suitable for rolling formation and a manufacture method of the super-high strength cold rolled steel belt. The super-high strength cold rolled steel belt comprises the following ingredients by weight percent: 0.12 to 0.18 percent of C; 0.1 to 0.4 percent of Si; 0.4 to 0.9 percent of Mn; 0.001 to 0.003 percent of B; 0 to 0.015 percent of P; 0 to 0.004 percent of S; 0.003 to 0.008 percent of N; 0.02 to 0.06 percent of Ti; 0.015 to 0.045 percent of Al; 0.002 to 0.006 percent of Ca; and Fe and unavoidable impurities in balancing amount. Through a reasonable ingredient design and a process design, the super-high strength cold rolled steel belt suitable for rolling formation is obtained; the tissue distribution is uniform; the performance uniformity is high; and a steel belt-type tissue is light and small, so that the cold bending performance is high. Moreover, the hardenability is moderate; the weld joint strength of the super-high strength cold rolled steel belt after being welded is approximately the same as that of a base metal; and the content of Si in the super-high strength cold rolled steel belt is lower, so that the surface quality of the super-high strength cold rolled steel belt is better, which meets the requirements for rolling and manufacturing vehicle components.

Description

technical field [0001] The invention relates to an ultra-high-strength cold-rolled steel strip and a manufacturing method thereof, in particular to an ultra-high-strength cold-rolled steel strip suitable for roll forming and a manufacturing method thereof. Background technique [0002] The automotive industry requires the use of higher strength steel plates for weight reduction. Among them, ultra-high-strength steel with a tensile strength of 980 MPa and above has increasingly become the first choice for the automobile manufacturing industry, because steel of this strength level can effectively reduce the weight of the automobile body and improve safety. Ultra-high-strength steel is more difficult to produce than ordinary-strength steel in steel mills, with high equipment requirements, high equipment loss, and difficult quality control. In the process of automobile manufacturing, high-strength steel plate is prone to cracking due to its high strength and low formability, so...

AI Technical Summary

Problems solved by technology

Due to the high content of C and Mn, it is very easy to form a large number of martensitic bands distributed in bands, resulting in uneven structure and properties, such as large anisotropy of bending properties

If it is used for rolling, there will be problems such as poor bending performance, uneven deformation, and varying degrees of springback, making it difficult to obtain ideal part shapes.

Some inventions also need to add expensive metals such as Cr and Mo, which increases the cost of steel

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