摘要
有一些粉末冶金(Cr,Mo)合金钢是由大量生产的Astaloy CrM粉末(3%Cr,0.5%Mo)制造的,并且烧结件具有不同的含氧量。对这些材料的显微组织与断口形态进行了分析。发现,氧一般是以Cr_2O_3颗粒析出,聚集在沿以前颗粒边界的平面上。这种空间形相(spatial configuration)控制着烧结颈塑性变形时的晶核形成与微小孔隙的间距,因此,含氧量增高时,韧性与疲劳强度都会大大减低。最后表明,用高温烧结可制成兼具高强度与韧性好的粉末冶金(Cr,Mo)合金钢。这是因为高温烧结可将这些材料的含氧量(质量分数)减小到<0.05%。
A number of（ Cr, Mo） -alloyed PM-steels was prepared from commercial powder（ 3 wt. % Cr,0. 5 wt. % Mo） and sintered to various oxygen levels. The microstructure and the fractographic appearance of these materials were analyzed. Oxygen being generally precipitated as particulate Cr2 03 was found to be concentrated in planes along former particle boundaries. This spatial configuration controls the nucleation and spacing of micro-voids during plastic deformation of sintering necks and significantly reduces ductility and fatigue resistance upon increasing oxygen content. Finally it is shown that（ Cr, Mo）-PM-steels combining both high strength and good ductility can be obtained by high temperature sintering which reduces the oxygen content of such materials below 0. 05wt. %.
出处
《粉末冶金技术》
CSCD
北大核心
2013年第5期385-391,共7页
Powder Metallurgy Technology
关键词
铬钢
韧性
断裂性状
chromium steels
ductility
fracture behavior
