工艺参数对双相不锈钢瞬间液相连接组织结构和等温凝固的影响

袁新建¹，罗军¹，李佳¹，KANG Chung-yun²

(1. 重庆大学 材料科学与工程学院，重庆，400044；
2. 釜山国立大学 材料工学部，釜山 609735，韩国)

摘 要：采用3种非晶态镍合金作中间层，对双相不锈钢进行瞬间液相连接试验研究。试验结果表明：采用MBF-30作中间层在1 060 ℃和300 s进行连接时，等温凝固完成，连接中间区以γ-Ni相为主，BN出现在基体与中间层的界面处。但是，MBF-35作中间层在1 060 ℃和300 s进行连接时，等温凝固未能完成，连接中心部含有Ni₃Si；采用MBF-50作中间层在1 175 ℃和300 s进行连接时，BN和(Cr，Ni)₃Si 相出现在连接中间区，等温凝固仍未能完成(等温凝固完成时间大于14 400 s)，而采用溶质分布模型计算结果仅为71 s。微观结构及等温凝固的差异归因于在较高温度下存在Si，N和Cr等合金元素并在连接中心处富集。

关键词：双相不锈钢；镍基非晶合金；瞬间液相连接；工艺参数；组织结构差异；等温凝固差异

Effects of bonding parameters on microstructure and isothermal solidification during transient liquid-phase bonding of duplex stainless steel

YUAN Xin-jian¹, LUO Jun¹, LI Jia¹, KANG Chung-yun²

(1. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. Department of Materials Science and Engineering, Pusan National University, Busan 609-735, Korea)

Abstract:An experimental investigation on transient liquid-phase bonding of a duplex stainless steel was carried out using Ni-based amorphous alloy as the interlayer. The experimental results show that using MBF-30 as the interlayer at 1 060 ℃ for 300 s, isothermal solidification is completed and the bonding region is mainly γ-Ni phase. However, using MBF-35 as the interlayer at 1 060 ℃ for 300 s, isothermal solidification is not completed and the joint center region is consisted of Ni₃Si. Using MBF-50 as the interlayer at 1 175 ℃ for 300 s, BN and (Cr, Ni)₃Si are present in the bond center zone and the isothermal solidification is still not completed, which takes longer than 14 400 s, whereas the time calculated by solute distribution model is only 71 s. The differences of microstructure and isothermal solidification originate from the appearance and enrichment of Si, Cr and N alloying elements in the bond center area at higher temperature.

Key words:duplex stainless steel; Ni-based amorphous alloy; transient liquid-phase; bonding parameters; microstructure variation; isothermal solidification discrepancy