耐火砖模具的稀土高浓度渗碳

Rare Earth High Carbon Potential Carburization of Firebrick Die

在煤油渗剂中添加微量稀土元素对A3钢耐火砖模具进行稀土高浓度渗碳 ,可使渗速加快 ,渗层碳浓度增高 ,层深尤其是过共析 +共析层深度增加 ;渗层硬度较高且硬度梯度较缓 ;渗层组织中的碳化物数量增多 ,且呈细小颗粒状弥散分布。生产实践表明 ,经该工艺处理的耐火砖模具 ,使用寿命可比常规气体渗碳处理的提高2— 3倍。

The kerosene carburizers with a few additive of rare earth were used to carbonize firebrick die of A3 steel. The rare earth high concentration carbonization can effectively enhance the carbonizing rate, increase the carbon concentration of the carbonizing layer, the layer depth, especially the depth of the hypereutectoid+eutectcid layer and the effective hardening layer are increased.The hardness gradient is slight. The amount of carbide is increased and is dispersed in the form of fine granular in the carbonized layer. The practical applications show that the service life of the A3 steel firebrick die carbonized by high concentration rare earth carbonization is increased by two to three times compared with that of conventional gas carbonization.