Heat Treatment Process of Micro Vanadium Cr-B System NM400 Wear-resistant Steel

Vanadium-based wear-resistant steels are an important class of wear-resistant materials due to their excellent wear resistance. NM400 wear-resistant steel belonging to this class has good wear resistance and excellent fatigue resistance. The processing parameters of wear-resistant steels are very important in order to obtain good performance. The heat treatment process of micro Vanadium Cr-B system NM400 wear-resistant steel is an important measure to improve its performance.
    
NM400 Wear Resistant Steel Introduction
NM400 wear-resistant steel is a kind of specially hardened low-carbon chromium-manganese-boron high-strength steel. It has excellent wear resistance, higher hardenability, good toughness and welding properties, and good toughness and plasticity in cutting.
    
Heat Treatment Process
The heat treatment process of NM400 wear-resistant steelCN is mainly quenching and tempering.The detailed process is as follows:
    
1. Forging. First preheat the steel to 800-850℃ and then perform slow heating to 1150-1300℃.
    
2. Quenching. In order to improve the wear resistance of the steel, it is necessary to quench it at a high temperature of 1150-1300℃.After cooling, the quenched part should be tempered and then heat treated at low temperature.
    
3. Tempering.The quenched parts should be tempered at a low temperature of 500-700℃ and then cooled in air.
    
4. Stress relief.After quenching and tempering, the parts should be heated to 600-850℃ and held for 2 hours, and then cooled in air.
    
Performance Improvement
The micro-alloying of vanadium, chromium, manganese and boron in NM400 wear-resistant steel can greatly improve its wear resistance and toughness. The heat treatment process has the positive effect of improving toughness and wear resistance while maintaining the strength and plasticity of the steel. Quenching at high temperature can refine the grain and increase the hardness of the steel, while tempering at low temperature can reduce stress, improve toughness and reduce brittleness. The stress relief process further reduces residual stress and improves the fatigue resistance of the steel.
    
In order to obtain good wear resistance and fatigue resistance performance, it is necessary to accurately control the heat treatment process during the process of micro-alloyed NM400 wear-resistant steel. The heat treatment process mainly consists of forging, quenching, tempering and stress relief. These processes can significantly improve the performance of the steel by refining the grain, enhancing the hardness, reducing the stress and improving the toughness.

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