A Study on the 43$0^{\circ}C$ Degradation Behavior of Cast Stainless Steel(CF8M)(I);Evaluation of Degradation mechanism, Static and Fatigue Strength

주조 스테인리스강 CF8M의 43$0^{\circ}C$ 열화거동에 관한 연구(I);열화기구.정적 및 피로강도평가

  • Published : 2000.08.01


The five classes of the thermally aged CF8M specimen are prepared using an artificially accelerated aging method. Namely, after the specimens are held for 100, 300, 900, 1800, and 3600hrs at 430$^{\circ}C$ respectively, the specimens are water-cooled to room temperature. The impact energy variations are measures for both the aged and virgin specimens through the Charpy impact tests in addition to the microstructure observation, tensile, hardness and fatigue crack growth tests. From the present investigation the following results are obtained : 1) The difference among the thermally degraded specimens can be distinguished through their microstructures, 2) Hardness and tensile strength are increased to 300hrs, degradation specimen, while elongation and reduction area are decreased to 3600hrs degradation specimen, and impact energy is decreased to 1800hrs degradation specimen, 3) The FCG rates for thermally degraded specimens are larger than that of the virgin specimen.


CF8M;Thermal Aging;Virgin Material;Degraded Material;Observation of Microstructure;Microhardness Test;Tensile Test;Impact Test;Fatigue Crack Growth Test


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