Vanadium microalloyed medium-carbon carbide-free bainite steel and preparation method thereof

Abstract

The invention discloses a preparation method of vanadium microalloyed medium-carbon carbide-free bainite steel, and relates to the technical field of steel preparation. The preparation method comprises the following steps that S1, a steel ingot is forged, wherein the steel ingot comprises the following components in percentage by weight: 0.38-0.42% of C, 1.4-1.6% of Si, 1.4-1.6% of Mn, 1.0-1.2% of Cr, 0.3-0.4% of Mo, 0.1-0.16% of V, and the balance Fe and other inevitable impurities; S2, the refined steel ingot is subjected to homogenization solution treatment at the temperature of 1050 + / -100 DEG C; S3, oil quenching is conducted, and an initialized martensite structure is obtained; S4, the temperature is increased to 1000-1050 DEG C, temperature keeping operation is carried out, and complete austenite is obtained; S5, the steel ingot is cooled to 840-950 DEG C, secondary temperature keeping is conducted, and precipitation of VC is controlled; and S6, the steel ingot is rapidly cooled to 300-350 DEG C, temperature keeping is carried out for the third time, and bainite phase change happens, so that a Fe-bainite structure is obtained. According to the preparation method of the vanadium microalloyed medium-carbon carbide-free bainite steel, the content of VC precipitates can be increased by lowering the temperature of secondary temperature keeping, and the bainite phase change speed can be increased by controlling precipitation of VC.

Description

technical field [0001] The invention relates to the technical field of steel preparation, more specifically, it relates to a vanadium microalloyed medium-carbon carbide-free bainite steel and a preparation method thereof. Background technique [0002] At present, foreign medium and low carbon alloy martensitic wear-resistant steels are mostly Cr, Mo and Ni alloy steels. The heat treatment process adopts the process of quenching and low temperature tempering to obtain alloy properties of high strength, high hardness and certain toughness. The research and application of medium and low carbon alloy wear-resistant cast steel in my country began after the 1980s, and a series of achievements have been made. The typical steel types are 30CrMnSiMoNi and Cr5Mo steel. The case of Si, Mn alloy 30Si2Mn. Now people have gradually realized that multi-element alloying is an effective method to improve the hardenability, strength, toughness and hardness of wear-resistant cast steel. Theref...

AI Technical Summary

Problems solved by technology

High manganese steel is a kind of austenitic steel with low initial hardness. Only under the action of large impact load or joint stress can it exert the surface work hardening phenomenon and play a role in wear resistance. However, in actual working conditions, More than 90% of the processes cannot harden high manganese steel effectively, making the actual wear resistance of high manganese steel unsatisfactory

Images