Ultrahigh-strength hot-rolled complex phase steel plate and steel strip with good bending and broaching performance and manufacturing method thereof

Abstract

The invention discloses an ultrahigh-strength hot-rolled complex phase steel plate and steel strip with good bending and broaching performance and a manufacturing method thereof. The ultrahigh-strength hot-rolled complex phase steel plate and steel strip comprise the following components in percentage by weight: 0.07-0.14% of C, 0.1-0.4% of Si, 1.55-2.00% of Mn, less than or equal to 0.015% of P, less than or equal to 0.004% of S, 0.01-0.05% of Al and less than or equal to 0.005% of N, and further comprises at least one of alloy elements of less than or equal to 0.07% of Nb, 0.02-0.15% of Ti and 0.10-0.20% of V, at least one of alloy elements of 0.15-0.50% of Cr and 0.15-0.50% of Mo, and the balance of Fe and inevitable impurities. The ultrahigh-strength hot-rolled complex phase steel has the tensile strength of above 800 MPa, the yield strength of above 700 MPa, the cold bending performance of 0a at 180 DEG C, the broaching rate of above 50%, and the microstructure of bainite (at least 80%) and a small amount of ferrite, martensite and retained austenite, wherein the bainite is mainly lower bainite. The ultrahigh-strength hot-rolled complex phase steel can be applied to manufacture of an automobile chassis, a hanging component, a bumper and other products.

Description

technical field [0001] The invention belongs to the field of metal materials, and relates to an ultra-high-strength hot-rolled multi-phase steel plate and a steel strip with good bending and hole expansion properties and a manufacturing method thereof, which are mainly used in manufacturing automobile chassis, suspension parts, bumpers and other products. Background technique [0002] The "light weight" of automobiles can directly reduce emissions and fuel consumption, which is the goal of the development of today's automobile manufacturing industry. Over the past decade, the weight of automobiles has increased year by year due to increased requirements in terms of comfort and safety features. An important measure of automobile "lightweight" is to use high-strength steel and ultra-high-strength steel plate instead of mild steel. After a large number of high-strength steels are used, a 20-25% weight reduction effect can be achieved. [0003] At present, ultra-high-strength ...

AI Technical Summary

Problems solved by technology

But this kind of steel has many problems in the process of hot-dip galvanizing

Images