고질소 오스테나이트계 스테인리스강의 인장물성에 미치는 변형속도의 영향 (Strain-rate Effect on Tensile Properties of High-nitrogen Austenitic Stainless Steel)

서지정보

· 발행기관 : 한국소성∙가공학회
· 수록지 정보 : 소성∙가공 / 33권 / 5호 / 322 ~ 329페이지
· 저자명 : 이승한, 김동욱, 김양곤, 강지현

초록

Because a high strain rate suppresses cross slip and delays dynamic recovery in the alloys with a face-centered cubic (FCC) structure, it is generally accepted that the influence of strain rate on strain hardening rate and tensile strength is greater than that on the yield strength of FCC alloys. The present study examined the tensile behavior of an austenitic stainless steel exhibiting an FCC structure, and revealed that the increment in yield strength was greater than that in tensile strength as the strain rate increased from 5.21×10-5 s-1 to 4.17×10-1 s-1. This indicated that the strain hardening rate was reduced by increasing the strain rate, which was inconsistent with the conventional explanation. Adiabatic heating was detected at high strain rates from 5.21×10-5 s-1, and the resulting temperature increase could elevate stacking fault energy. The tendency for sip planarity was investigated by applying the Ludwigson model to the tensile curves, which suggested that higher stacking fault energy due to adiabatic heating could accelerate cross slip and dynamic recovery, thereby reducing the strain hardening rate.

영어초록

Because a high strain rate suppresses cross slip and delays dynamic recovery in the alloys with a face-centered cubic (FCC) structure, it is generally accepted that the influence of strain rate on strain hardening rate and tensile strength is greater than that on the yield strength of FCC alloys. The present study examined the tensile behavior of an austenitic stainless steel exhibiting an FCC structure, and revealed that the increment in yield strength was greater than that in tensile strength as the strain rate increased from 5.21×10-5 s-1 to 4.17×10-1 s-1. This indicated that the strain hardening rate was reduced by increasing the strain rate, which was inconsistent with the conventional explanation. Adiabatic heating was detected at high strain rates from 5.21×10-5 s-1, and the resulting temperature increase could elevate stacking fault energy. The tendency for sip planarity was investigated by applying the Ludwigson model to the tensile curves, which suggested that higher stacking fault energy due to adiabatic heating could accelerate cross slip and dynamic recovery, thereby reducing the strain hardening rate.

참고자료

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