S32760双相不锈钢Co基等离子堆焊组织耐腐蚀性研究

Microstructure and Corrosion Resistance of Plasma Bead Welding of Cobased Material on S32760 Duplex Stainless Steel

采用等离子堆焊技术,在S32760双相不锈钢表面堆焊Stellite 12 Co基合金熔覆层,研究了其微观组织、硬度及耐腐蚀性。结果表明,S32760双相不锈钢堆焊Stellite 12 Co基合金后,堆焊层主要由枝晶状γ-Co固溶体和花瓣状枝晶间γ-Co与碳化物共晶组织组成;由于等离子堆焊基体稀释率小,堆焊后热影响区范围小,因此没有出现明显的热影响区硬度高于母材硬度的现象,合金堆焊层硬度在490～510 HV;母材和合金堆焊层表现出良好的耐腐蚀性。

Stellite 12 of Co based alloy powder was deposited on the surface of S32760 super duplex stainless steel by plasma bead welding. The effect of heat treatments on microstructure, hardness and corrosion resistance of Stellite 12 coating on S32760 substrate was investigated. The results show that after plasma bead welding of S32760 duplex stainless steel with Stellite 12 of Co based alloy powder, the alloy surfacing layer structure is mainly composed by dendritic γ-Co solid solution, petal-like interdendritic γ-Co and carbide eutectic. Due to the small dilution of plasma surfacing matrix, the HAZ after bead welding is small and no obvious hardening appears. The hardness of alloy surfacing layer is about 490-510 HV. And the base metal and alloy surfacing layer show good corrosion resistance.