论文部分内容阅读
研究了经脉冲电流和常规电阻炉奥氏体化热处理后30钢晶粒大小的变化,结果表明在同等的奥氏体化加热温度和加热时间及冷却速度的实验条件下,经电阻炉处理后试样的金相组织与原始组织相同即仍为先共析铁素体加珠光体组织,而经脉冲电流处理后的试样其金相组织则为魏氏组织.经过深入分析魏氏体组织的形成条件及对晶粒尺寸的比对,可知经脉冲电流热处理后的试样的奥氏体化的晶粒较常规热处理的晶粒要粗大得多,进一步的理论分析显示:促使奥氏体晶粒显著长大的机制在于脉冲电流增大了原子的扩散系数从而促进了原子扩散所致.该结论提示,脉冲电流显著促进了钢的奥氏体化过程,脉冲电流条件下的奥氏体化热处理的温度与时间与常规的热处理工艺参数相比将大为降低和减少,从而大幅度节省能源与提高效率.
The changes of the grain size of 30 steel after pulse current and conventional resistance furnace austenitizing heat treatment were studied. The results show that under the same austenitizing heating temperature, heating time and cooling rate, The microstructure of the sample is the same as that of the original one, that is, the first pro-eutectoid ferrite plus pearlite and the microstructure of the sample after pulse current treatment are Wei’s tissue. The formation conditions and the comparison of the grain size shows that the austenitized grain size of the sample after the pulse current heat treatment is much larger than that of the conventional heat treatment. Further theoretical analysis shows that the austenite The mechanism of significant grain growth is that the pulsed current increases the atomic diffusion coefficient and thus promotes the atomic diffusion.The conclusion suggests that the pulse current significantly accelerates the austenitization process of steel and the austenite Heat treatment temperature and time compared with the conventional heat treatment process parameters will be greatly reduced and reduced, resulting in significant energy savings and improve efficiency.