摘要
用单相Ｃ０及只在晶界上有碳化物析出Ｃ２的两种Ｆｅ－１５Ｃｒ－２６Ｎｉ奥氏体合 金，在应力３９．２ ＭＰａ，温度 １１２３ Ｋ下，研究了晶粒尺寸及晶界碳化物对蠕变断裂 性质的影响。结果表明：两种合金的最小蠕变速率ｅｍ及断裂时间ｔｒ很好地符合 Ｄｏｂｅｓ－Ｍｉｌｉｃｋａ关系即：是断裂应变。Ｃ０与Ｃ２合金在研究的 晶粒尺寸范围内（２０－３００μｍ），断裂应变差别不大，但Ｃ２合金的断裂时间比Ｃ０合 金长一个数量级。Ｃ０合金断裂时间与断裂应变都在晶粒尺寸约４０μｍ的有最大值。 Ｃ合金断裂时间则在晶粒尺寸约８０μｍ时有最大值，但断裂应变与晶粒尺寸无关。 文中还探讨了它们随晶粒尺寸变化的原因。
Creep rupture properties have been investigated at 39.2 MPa, 1 123 K in two Fe-15Cr-25Ni austenitic alloys (called C0 and C2 respectively). C0 is a single phase solid solution.C, is a two-phase alloy in which carbide precipi- tates are only formed at grain boundaries. Results indicate that the relations between minimum creep rate εm and time to rupture tr in two alloys are in good agreement with the Dobes-Milicka relation, i. e. εmtr.εf=0.64, where εf is the strain to failure. The values of strain to failure in two alloys are similar for the examined grain size range (20-300 μm), but the time to rupture of C2 alloy is about an order of magnitude longer than that of C0 alloy. The maximum strain to failure and maximum time to rupture are found at a grain size of about 40 μm in the C0 alloy. The C2 alloy has a maximum time to rupture at a grain size of about 80 μm, but its strain to failure is independent of grain size. The reason of the variation of creep rupture prop- erties with grain size in two alloys has also been discussed.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
1989年第5期547-553,共7页
Journal of Dalian University of Technology
关键词
晶粒
晶界
碳化物
蠕变断袭
austenitic alloys
grain size
grain boundary
carbide
creep rupture
