Microstructure and wear resistance of martensitic wear-resistant steel and bainite wear-resistant steel

Wear-resistant steel is an important material for engineering components which needs to operate in harsh environment. Low alloy martensitic and bainite wear-resistant steels have become an alternative to traditional high carbon steels and hardfacing materials since they benefit from increased wear resistance, toughness and strength.
    
Microstructure characteristics of martensitic and bainite wear-resistant steels
    
The microstructure of martensitic and bainite wear-resistant steels is a key contributor to their wear resistance. The microstructure of steel greatly influences its physical and mechanical properties, so a thorough understanding of the microstructural evolution of these steels is essential for optimizing the wear resistance of engineering components.
    
The microstructure of martensitic wear-resistant steel consists of hard and fine martensite. The hard martensite forms a continuous network providing the high wear resistance of the steel. The fine martensite has a lower hardness than the hard martensite and decreases the brittleness of the steel. In addition, there are small amounts of retained austenite which provides the elasticity of the steel.
    
The microstructure of bainite wear-resistant steel consists of bainite, pearlite and small amounts of ferrite. The bainite provides the high wear resistance of the steel. The pearlite/ferrite matrix provides high toughness and strength.
    
Microstructure of martensitic wear-resistant steel and bainite wear-resistant steel
    
Wear resistance of martensitic and bainite wear-resistant steels
    
Martensitic wear-resistant steel provides high wear resistance due to the hard martensite. The hardness of the hard martensite is usually in the range of 55-60 HRC (Rockwell hardness) and the hardness of the fine martensite is usually in the range of 30-35 HRC. The retained austenite contributes to the elasticity of the steel.
    
Bainite wear-resistant steel has a low hardness of typically less than 40 HRC and high toughness due to the bainite, pearlite and ferrite matrix. Bainite wear-resistant steel provides a balance between wear resistance and toughness, making it suitable for severe wear applications.
    
Wear resistance of martensitic and bainite wear-resistant steels

Martensitic and bainite wear-resistant steels provide an excellent combination of strength, hardness and wear resistance. The microstructure of martensitic wear-resistant steel consists of hard martensite and fine martensite, and the microstructure of bainite wear-resistant steel consists of bainite, pearlite and ferrite. Martensitic wear-resistant steel has a high hardness and high wear resistance, while bainite wear-resistant steel has a lower hardness and provides a balance between wear resistance and toughness.

---