A crash-resistant hot-formed martensitic steel favoring optimization of retained austenite

Abstract

The invention discloses anti-crash hot forming martensitic steel facilitating optimization of retained austenite. The anti-crash hot forming martensitic steel facilitating optimization of the retained austenite is characterized by comprising the following main chemical components in percentages by weight: 0.1-0.35 of C, 1.5-3.5 of Mn, 1.0-2.5 of Al, 0.5-1.25 of Si, 0.2-0.8 of Cu, 0.3-0.7 of Cr, 0.01-0.05 of Nb, 0.005-0.02 of Zr, 0.001-0.005 of B, 0.005-0.01 of Ti, 0.02-0.08 of Mo, 0.001-0.005 of RE, less than or equal to 0.04 of N, less than or equal to 0.01 of P, less than or equal to 0.005 of S and the balance of Fe, wherein (Al+Si) is greater than or equal to 2.0, and Si / Al is less than or equal to 0.5. The hot forming martensitic steel material is suitable for increasing the content of the retained austenite and optimizing morphology and distribution of the retained austenite by the traditional hot forming technology.

Description

technical field [0001] The invention relates to the technical field of alloy steel, in particular to an anti-collision hot-formed martensitic steel which is beneficial to optimize retained austenite. Background technique [0002] In response to the current increasingly prominent energy crisis and environmental pollution problems, higher requirements are put forward for the lightweight of transportation vehicles. While reducing the weight of the vehicle itself, the improvement of safety and reliability has become the main goal of reducing the weight of the vehicle. The widespread use of high-strength or ultra-high-strength steel is one of the important and effective ways to reduce vehicle weight. Due to the high rigidity, high resilience, high forming force and easy cracks of high-strength steel, thermoforming technology emerged as the times require, and the problems of difficult forming, severe springback and poor dimensional accuracy of high-strength steel have been solved...

AI Technical Summary

Problems solved by technology

However, the Si content of these steels is high, and when the steel plate is hot rolled, a very stable Mn will be formed on the surface. 2 SiO 4 These oxide scales are easy to roll into the surface of the steel plate and are difficult to remove by pickling, thereby deteriorating the coating performance of the hot-formed steel plate surface, reducing the quality of the coating, and causing defects such as oxide scale on the surface during hot forming

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