Hot-rolled dual-phase steel in 590MPa tensile strength grade and method for manufacturing hot-rolled dual-phase steel

Abstract

The invention discloses hot-rolled dual-phase steel in the 590MPa tensile strength grade and a method for manufacturing the hot-rolled dual-phase steel. The steel comprises, by weight, from 0.04% to 0.10% of C, from 1.10% to 1.50% of Mn, from 0.10% to 0.20% of Si, from 0.015% to 0.070% of Als, from 0.03% to 0.08% of P, lower than or equal to 0.008% of S, from 0.5% to 1.2% of Cr, the balance Fe and inevitable impurities. The method for manufacturing the steel includes molten iron desulfurization, converter smelting, vacuum treatment, continuous casting, sizing, plate blank heating, hot continuous rolling, laminar cooling and reeling. As proved by practice, the steel is high in tensile strength, low in yield ratio and excellent in cold stamping forming performance and fatigue resistance, a technological process of the method is simple, and the production cost is low.

Description

technical field [0001] The invention belongs to the technical field of steel plate production, and specifically refers to a hot-rolled dual-phase steel with a tensile strength of 590 MPa and a manufacturing method thereof. Background technique [0002] Reducing the weight of the vehicle body by increasing the strength of the steel plate, reducing consumption, saving energy, and reducing environmental pollution are important topics in the research of today's automobile industry. While continuously improving the strength of the steel plate, it should also have good toughness, fatigue resistance, and good bending and flanging performance. The wheel is a rotary moving part, and its weight reduction and energy saving effect is 1.5 times that of other parts. By using high-strength wheel steel to produce wheels, the weight can be reduced while ensuring the performance requirements, and a good energy-saving and environmental protection effect can be achieved. [0003] There are ma...

AI Technical Summary

Problems solved by technology

In order to ensure the formability of parts, the amount of martensite is generally controlled between 8 and 25%. If the amount of martensite is too much, the strength is too high and the formability is poor, which is not conducive to the high requirements for formability of complex parts.

The amount of martensite is less, the formability is good, but the strength is low, and the fatigue performance of the parts cannot meet the design requirements

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