夹杂物特征参数对40CrNi2Mo钢塑性的影响

用定量金相、扫描电镜和能谱分析等方法获取了用2种工艺冶炼的40CrNi2Mo钢中夹杂物尺寸特征参数,研究了这些参数对钢塑性的影响。结果表明:由于夹杂物的体积分数和尺寸比较小,夹杂物间距的增大,在塑性断裂时由夹杂物形成的微孔洞很难以内颈缩形式聚合,微孔洞间的局部剪切也不容易扩展。由此判断,真空自耗重熔钢的断面收缩率比电渣重熔钢的高。钢中的夹杂物对其均匀延伸率、形变硬化指数和拉伸强度没有影响。

Influence of Characteristic Inclusion Parameters on Ductility of 40CrNi2Mo Steel

The influence of characteristic inclusion parameters on ductility of 40CrNi2Mo steels produced by different metallurgy processes were analyzed by quantitative metallography, SEM and EDAX. Results show that decreasing the volume and size of inclusions and increasing the spacing of inclusions, the void nucleated by the inclusions coalescence by internal necking and the development of localized shearing between voids became more difficult in ductile fracture, so percentage reduction of area of VAR steels were better than ESR steel. Characteristic inclusion parameters had little effect on uniform elongation, strain hardening exponent and tensile strength.