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Vol.45, No.5, 269 ~ 278, 2007
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| Title |
| Aging Behavior of High Nitrogen Austenitic Stainless Steel |
| 김성준 Sung Joon Kim , 이태호 Tae Ho Lee , 오창석 Chang Seok Oh , 박익민 Ik Min Park , 방해중 Hae Jung Bang |
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| Abstract |
| Time-temperature-precipitation (TTP) characteristics of high nitrogen austenitic Fe-18Cr-18Mn-2Mo-0.9N stainless steel (all in weight percent) were investigated in terms of precipitation behavior, and crystallographic features of the second phases. The precipitation reactions can be categorized into three stages, i.e. (i) high temperature region (above 950℃): mainly coarse grain boundary (intergranular) Cr2N; (ii) nose temperature region: intergranular Cr2N→cellular Cr2N→intragranular Cr2N+sigma(σ); (iii) low temperature region (below 750℃): intergranular Cr2N→cellular Cr2N→intragranular Cr2N+σ+chi(χ)+M7C3 carbide, respectively. Based on the analyses of selected area diffraction (SAD) patterns, the crystallographic features of the second phases were determined: (i) Cr2N (trigonal, P31m)-[001]y∥[1100]Cr2N,(111)y∥(0001)Cr2N; (ii)χ(b.c.c., I43m)-K-S orientation relationship; (iii) M7C3 (orthorhombic, Pnma)-[001]γ∥[101]M7C3,(111)y∥(131)M7c3. |
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| Key Words |
| time-temperature-precipitation, TTP, high nitrogen steel, HNS, Cr2N, M7C3 carbide and crystallography |
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