渗碳对KHR35CT-HiSi钢性能的影响

Carburization Effect on Mechanical Character of KHR35CT-HiSi Steel

本文对乙烯裂解炉管材料KHR35CT-HiSi离心铸造奥氏体钢在不同服役温度下的渗碳行为进行了研究。结果表明:KHR35CT-HiSi钢初始的连续骨架状碳化物结构渗碳之后转化为不连续的链状。渗碳层区域呈现出富Ni、Fe和贫Cr区,并且已渗碳试样的表面与中心区域呈现较大的碳浓度和合金成分梯度,对热疲劳和热冲击的敏感性增加。

Carburization behavior of centrifugally cast KHR35CT-HiSi austenitic steel used for manufacturing ethylene cracking furnace tube at different operating temperatures was studied in this paper. The results showed that the virgin continuous framework of eutectic carbide converted into the block or strip structure. Ni-rich, Fe-rich and Cr- depleted zones were detected at the carburization layer. Concentration gradient of carbon and alloy elements existed between the surface and core zone of the carburized sample, which causes KHR35CT-HiSi steel sensitive to thermal fatigue and thermal impact.