Nb 첨가량에 따른 436 페라이트계 스테인리스강 용접부의 미세조직변화 및 공식 저항성에 관한 연구

• Published in: 대한금속·재료학회지, 52(12) pp. 995 - 1002
• Main Authors: Jong-Min Kim, Yong-Taek Shin, Sang-Hwa Lee, Jun-Hee Lee, Sung-Riong Lee, Soon-Ho Kim, Hae-Woo Lee
• Format: Journal Article
• Language: Korean
• Published: 대한금속·재료학회 01.12.2014
• Subjects: 재료공학
• ISSN: 1738-8228; 2288-8241
• DOI: 10.3365/KJMM.2014.52.12.995

This paper identified the effects of Nb on microstructure. Also, it has studied on uniform andpitting corrosion resistance in a ferritic stainless steel weld metal of the automobile exhaust system. Wefabricated 3 flux cored wires designed with 0-1.0 wt% Nb and performed Flux Cored Arc Welding. Weobserved the microstructure with the SEM/EDS and EBSD. To evaluate the uniform and pitting corrosionresistance, we performed a potentiodynamic polarization test in 0.2 M H2SO4 and 0.1, 0.3, 0.5 M NaCl. Asa result of the tests, we found that as the amount of addition of Nb rose, the amount of Cr-carbide fell. Themicrostructure became more refined. The specimen with 1.0%Nb added had the highest uniform and pittingcorrosion resistance. After the pitting corrosion test, a pit was formed at the grain boundary that has noaddition of Nb. In addition, in the specimen with added Nb, pits were formed at the inclusions. KCI Citation Count: 2