一种新型高强韧性耐磨钢的纳米结构原子像及其性能

Nanostructure atomic image and mechanical properties of a novel wear resistance steel with high strength and toughness

研制的新型高强韧性耐磨钢 ,铸态空冷及淬火回火处理均可获得细小或隐晶马氏体 ,少量贝氏体和残留奥氏体以及碳化物 .铸态淬火回火处理样品的U 型缺口冲击韧度аk =38～ 5 0J cm2 ,无缺口冲击韧度аk =14 0～ 2 90J cm2 ,HRC =5 3～ 5 6 ;锻后淬火回火处理样品U 型缺口冲击韧度аk=5 0～ 70J cm2 ,HRC =5 2～ 5 4 ,抗拉强度σb=185 0～ 2 0 0 0Mpa .所研制钢的冲击韧度较相近成分的贝氏体钢提高 4 0 % .采用高分辨电镜对新型钢的纳米结构原子像进行了观察 ,确定了贝氏体铁素体亚片条尺寸 .

The microstructures of medium carbon wear resistance steel after quenching and tempering are martensite and small amount of bainite, retained austenite and carbide. The impact toughness with U notch as cast afrer air cooled was within 38～50?J/cm 2, and the impact toughness without notch was 140～290?J/cm 2. with hardness HRC =53～56; while in forged stage, their hardness was HRC =52～54, the impact toughness with U notch was 50～70?J/cm 2, and the tensile strength σ b =1850～2000?Mpa. The impact toughness of the studied medium carbon low alloy steel containing martensite, bainite and small amount of retained austenite is 40% higher than that of normal Mn B and Mn Si B bainitic steels. The nanostructure atomic image of the steel was observed with high resolution electron microscopy and the sizes of subplate of bainitic ferrite were determined.