http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
SCM440(H) 및 SNCM439 강의 열처리 특성에 미치는 질량효과
남기석 ( K. S. Nam ),현양기 ( Y. K. Hyun ),조창용 ( C. Y. Jo ),조유종 ( Y. H. Cho ) 한국열처리공학회 2011 熱處理工學會誌 Vol.24 No.1
Recently, renewable energy sources such as wind turbine, solar cell are interested in preventing global warming which is caused by the consumption of fossil fuel. SCM440H and SNCM439 have been used in the major components of the wind turbine gear because of excellent mechanical properties. In the present study, the heat treated mechanical properties of SCM440H and SNCM439 with 150mm diameter were compared with those with 25 mm diameter which is generally accepted material for structural application. Heat treated SCM440H showed better mechanical properties such as tensile strength, hardness and impact absorbed energy compared with those in SNCM439. Hardenss value between as-quenched and as-quenched followed by tempering showed big difference in SNCM439, however the difference in SCM440H was relatively small. Heat treated mechanical properties of the alloys with 25mm diameter were more uniform value than those with 150mm diameter. (Received November 3, 2010; Accepted November 29, 2010)
열처리공학회지,제27권 제1호(2014) -고온 가스질화 된 STS 430 스트인리스강의 냉간 가공성에 미치는 항온변태 열처리 시간 변화의 영향
김정민 ( J. M. Kim ),현양기 ( Y. K. Hyun ),송상우 ( S. W. Song ),김기동 ( G. D. Kim ),손영호 ( Y. H. Son ),성장현 ( J. H. Sung ) 한국열처리공학회 2014 熱處理工學會誌 Vol.27 No.1
This study is to investigate the phase changes and cold workability after isothermal transformation at l800C by using the high temperature gas nitrided (HTGN) STS 430 ferritic stainless steel specimens. The phase diagram of STS 430 steel obtained by calculation showed that the phase appeared at 11 OO°C showed as α + г →г+ Cr₂N →г+ Cr₂N + CrN with increasing nitrogen concentration. Also. the transformation of г→ Cr₂N during heat treatment isothermally at 780°C, nitrogen pearlite with lamellar type was fully formed at the nitrogen permated surface layer for 10 hrs. However. this transformation was not completed for 1 hr, resulting nitrogen pearlite plus martensite. The cold rolled specimen of isothermally transformed at l80°C for 10 hrs after high temperature gas nitriding decreased the layer thickness of nitrogen pearlite inducing the deformation of hard Cr₂N phase. the dissolution rate of Cr₂N phase increased rapidly with increasing cold rolling ratio. Specimens with the microstructure of nitrogen pearlite (isothermally transformed at l80°C for 10 hrs) were possible to cold rolling without crack formation. However, the mixed structures of nitrogen pearlite + martensite (isothermally transformed at 780°C for 1 hr) were impossible to cold deformation without cracking.