铈对D6冷作模具钢中共晶碳化物的影响

Effects of Cerium on Eutectic Carbides in Cold Working Die Steel D6

针对某集团生产的模铸D6钢中经常出现共晶碳化物对超标现象,在模铸过程中添加稀土元素铈。在坯料和钢材上取样,采用光学显微镜观察侵蚀后钢的组织形貌。结果表明,随着铈含量的增加,共晶碳化物网格尺寸变小,当坯料中铈含量由0.038%增加到0.073%时,网格尺寸减小约50%,网格厚度变薄,甚至网状结构被破坏;钢材中共晶碳化物的级别随铈含量的增加而降低。铈对铸态组织的细化作用导致了最终产品中共晶碳化物的细化。

To refine coarse eutectic carbides in cold working die steel D6, rare earth metal cerium was added during cast process. Samples were obtained from bloom steels and rolled products, and erosion microstructures were observed by optical microscope. The results show that the size of carbides net reduces with larger cerium content, and reduces about 50 % when cerium composition raises from 0. 038% to 0. 073%, the thickness of carbides net becomes thinner and even network is broken. The grades of eutectic carbides in the steel reduce with cerium adding. The action of cerium on refinement of as-cast structure results in refined eutectic carbides in product.