S含量对中碳非调质钢拉伸性能的影响

Effect of sulfur content on tensile property of medium carbon non-quenched and tempered steel

利用真空感应炉冶炼不同S含量的中碳非调质钢,锻后进行纵向及横向室温拉伸性能测试,研究了S含量对非调质钢拉伸性能的影响。结果表明,随S含量由0.025%增加到0.065%,钢中Mn S的数量增加,且锻后沿锻造方向发生明显伸长,同时晶粒得到一定细化。随S含量的增加,非调质钢的纵向拉伸强度基本不变,而横向性能则逐渐降低且明显低于纵向性能。横向拉伸过程中外加载荷垂直于钢中的长条形Mn S,Mn S容易与基体分离从而导致裂纹的产生,危害横向性能。

The longitudinal and transverse tensile tests were conducted at room temperature to study the effect of S content on the tensile property of medium carbon non-quenched and tempered steel.The results show that with the increase of S content from 0.025％ to 0.065％,the number of elongated MnS inclusions increases and the microstructure becomes much finer.The increasing S content has little effect on the longitudinal tensile strength of the steels,while it lowers the transverse tensile strength distinctly,which is due to the MnS inclusions separating from the Fe matrix with the applied load perpendicular to elongated MnS during transverse tensile tests.