大断面Si-Mn-Cr系高碳低合金耐磨钢淬火组织性能

Quenched Microstructure and Properties of Large Section Si-Mn-Cr High Carbon Low Alloy Wear-resistant Steel

对于Ф120mm的厚断面Si-Mn-Cr系低合金耐磨钢，研究了GN-4A以及60Si2CrA和45Cr三种耐磨钢由表层至心部的淬火组织，测得了由表至里的硬度分布，并分析了各工件心部的冲击韧度。结果表明：GN-4A耐磨钢被完全淬透，60Si2CrA半马氏体深度为30-40mm，心部为贝氏体和少量的珠光体及马氏体组织，45Cr半马氏体深度不到20mm，心部显微组织主要为珠光体和少量的贝氏体；就淬透性来讲，GN-4A专用耐磨钢最高，45Cr最差；就硬度和心部的冲击韧度综合性能而言，60Si2CrA最高，GN-4A专用耐磨钢次之，45Cr最差。

For the thick-section Si-Mn-Cr low alloy wear-resistant steel with the diameter of 120 mm, such as GN-4A, 60Si2CrA and 45Cr, quenched microstructure was studied from the surface to the heart of the cylinder specimen, hardness was measured from the surface to the heart, and the impact toughness of the heart was analyzed. The results show that GN-4A is completely quenched, half martensite depth of 60Si2CrA is 30-40 mm, the core is hainite and a small amount of pearlite and martensite, and half martensite depth of 45Cr is less than 20 mm, the core is pearlite and a small amount of bainite. As for hardenability, GN-4A is the best, 45Cr is the worst.On the comprehensive performance of hardness andimpact toughness of the heart, 60Si2CrA is the best, 45Cr is the worst.