球墨铸铁预处理对表面激光重熔层开裂倾向的影响

The effect of spheroidal graphite iron preheating on the creaking susceptibility of the surface laser remelted layer

对球墨铸铁表面激光重熔过程中的重熔层开裂倾向及影响因素进行了详细的研究,通过对基体分别进行正火、淬火+回火后进行激光表面重熔的对比试验,考察了在相同的激光重熔工艺参数条件下进行表面重熔处理,发现球铁激光重熔处理前的预处理工艺对重熔过程中的重熔层开裂倾向影响很大,试验结果表明预处理可以改变激光重熔时热影响区的大小、相变产物的显微组织形态,从而改变重熔层的相变应力的分布与大小,进而影响到激光重熔层的开裂倾向。为制定球铁激光重熔预处理的最佳工艺规范提供依据。

The remelted layer cracking susceptibility and its influencing factor during laser remelting the spheroidal graphite iron surface have been studied in detail. The contrast test was carried out for laser surface remelting varying substrate preheating. One is normaliz, the other is quench and temper. The surface remelting process with the same laser remelting processing parameters have been investigated. It was found that the effect of the spheroidal graphite iron preheating on cracking susceptibility of remelted layer was very great. The results were shown that the preheating is able to change the size of the heataffected zone which was formed during laser remelting and the microstructure of the phase transformation product. The distribution and the size of the phase transformation stress in the remehed layer are changed. And it affects the cracking susceptibility of the remelted layer. Then it provided the best adjustment rule of the processing parameters.