Microstructure Evolution and Precipitates Transformation in a Duplez Stainless Steel Bond Brazed with a Ni-B-Si Foil
MBF-35 (Ni-7.3Si-2.2B (wt.％)) was selected as a filler alloy for brazing of a duplex stainless steel conducted at the temperature range of 1060-1090 ℃ with various times from 60 s to 3600 s. The experimental results revealed that there was no significant grain growth of ferrite and austenite in the base metal. The precipitation of σ phase was not found in any of the brazed bonds. The results also indicated, prior to completion of isothermal solidification, BN and Ni3Si appeared in the brazing-affected zone and the bonded interlayer, respectively. The noted enrichment of Ni and Fe was detected in the brazing-affected zone. At 1060 ℃ and 1090 ℃ after 2700 s and 900 s, respectively, the isothermal solidification of the melt was completed at the center of the joints. The brazing was finished within 1200 s and 3600 s, respectively. The SEM and EPMA results also showed the transformation of secondary-phase precipitates from BN to BN and (N, Mo) boride and further to BN at the interface with increasing holding time. This transformation appeared to be largely due to the change in N composition with increase of holding time at the interface. BN precipitate was not removed in terms of the increased holding time at the bonding temperature. The formation of Ni3Si and BN was responsible for the appearance of hardness peak values in the joint area.
Brazing Duplez stainless steel Ni-B-Si amorphous alloy Microstructure Transformation
Xinjian Yuan Myung Bok Kim Chung Yun Kang
School of Materials Science and Engineering,Pusan National University,Busan,Republic of Korea National Core Research Center(NCRC)for Hybrid Material Solution,Pusan National University,Busan,Repu School of Materials Science and Engineering,Pusan National University,Busan,Republic of Korea Nation
国际会议
The Fourth Asian Conference on Heat Treatment and Surface Engineering(第四届亚洲热处理及表面工程大会)
北京
英文
171-175
2009-10-27（万方平台首次上网日期，不代表论文的发表时间）