深冷处理对SDC99冷作模具钢内耗行为的影响

Influence of deep cryogenic treatment on internal friction of SDC99 cold work die steel

研究了深冷处理时间和深冷循环次数对SDC99冷作模具钢内耗行为的影响,采用耦合模型理论对SKK(Snoek-Kê-K9ster)弛豫强度的变化机制进行了解释。结果表明:对于深冷未回火试样和深冷后回火试样,随着深冷时间的增加,SKK峰升高,其中深冷8 h后SKK峰最高,而深冷时间继续延长,SKK峰逐渐降低;随着深冷循环次数的增加,SKK峰升高,但仍低于深冷8 h的SKK峰。结合TEM结果发现,深冷处理可以促进回火过程析出更多的细小碳化物。

Influence of deep cryogenic treatment（ DCT） on internal friction of SDC99 cold work die steel was studied,and the change of relaxation strength of Snoek-Kê-K9ster（ SKK） peak was interpreted by a coupling model. The results indicate that the SKK peak height for both samples deep cryogenic treated without tempering and that with tempering increases with the increase of the cryogenic time then reaches its maximum after 8 h DCT,but with the further increase of the cryogenic time,the SKK peak is damping. With the increase of cryogenic cycles,the SKK peak height increases,however,it is lower than that of 8 h DCT. Combined with the TEM results,it is found that cryogenic treatment can promote the precipitation of carbides during tempering.