【摘要】 在650℃采用等径弯曲通道变形(ECAP)方法对原始组织为层片状珠光体的GCr15钢进行了Bc方式的多道次变形。采用透射电镜和洛氏硬度等实验方法,对不同道次下的组织特性和硬度进行了分析。结果表明:冷变形和温变形都能使渗碳体片层发生球化,但一道次温变形情况下渗碳体球化程度明显高于冷变形一道次,硬度值由原始态(层片状珠光体)的42 HRC分别降至38 HRC(冷变形)、27 HRC(温变形),温变形二道次后,铁素体基体接近等轴状,平均晶粒尺寸约为0.4μm,球化完全的渗碳体颗粒粒径约为0.1μm,硬度值由27 HRC(温变形一道次)增至32 HRC左右。更多还原

【Abstract】 Processing of a GCr15 steel with fully pearlitic structure was carried out by equal channel angular pressing(ECAP) via route Bc at room temperature and 650 ℃.Microstructure of the steel by ECAP for different passes was analyzed by transmission electron microscopy and its hardness was measured.The results show that after one pass,the degree in spheroidization of cementite by warm deformation is higher than that of cementite by cold deformation,and the hardness decreases from 42 HRC for the microstructure of fully pearlitic to 38 HRC for the microstructure of cold deformation and 27 HRC for the microstructure of warm deformation,although the spheroidization of cementite occurs during both cold deformation and warm deformation.Furthermore,after two passes by warm deformation,the microstructure of ferrite matrix is nearly homogeneous with an average grain size of 0.4 μm and the size of spherical cementite is about 0.1 μm,and also the hardness increases from about 27 HRC(one pass by warm deformation) to 32 HRC.更多还原