ASTM Gr.92강의 미세조직 및 기계적 성질에 미치는 템퍼링 온도 및 열처리경로의 영향

• Published in: 대한금속·재료학회지, 48(1) pp. 39 - 48
• Main Authors: 김연근, 한창희, 백종혁, 김성호, 이찬복, 홍순익
• Format: Journal Article
• Language: Korean
• Published: 대한금속·재료학회 01.01.2010
• Subjects: 재료공학
• ISSN: 1738-8228; 2288-8241

In order to investigate the effects of tempering temperature and heat-treatment path on the microstructural and mechanical properties of ASTM Gr.92 steels, four samples with different tempering temperatures and heat-treatment paths were prepared. Three experimental steels showed tempered martensitic microstructures, but the sample tempered at 810℃ was presumed to retain partially untempered martensitic microstructures due to a lower α+γ phase regime. M23C6, V(C,N), and Nb(C,N) precipitates were observed in all samples. In addition, Cr2N was observed to be precipitated finely and uniformly by isothermal heat-treatment. The lath width and precipitate size increased with an increase of the tempering temperature. In particular, the lath width and precipitate size in the isothermal heat-treated samples were much smaller than those of the tempered-only specimens. Because of a fine and uniform precipitate, a reduction of lath width would enhance precipitation hardening, and it was shown that mechanical propertiesincluding the hardness and tensile properties of the steels were improved by isothermal heat-treatment. KCI Citation Count: 4