CRACK GROWTH BEHAVIOR AND FRACTURE FEATURE OF GH2132 UNDER CREEP-FATIGUE CONDITIONS

查看全文 作　　者：Geng, [1]M.F. 机构地区：[1] Luoyang Ship Material Research Inst, Luoyang, China 出　　处：《Acta Metallurgica Sinica(English Letters)》索引1997年第10卷第6期,共6页 摘　　要：The crack growth behavior and fracture feature of superalloy GH2132 (equivalent to A286) under creep-fatigue conditions have been studied in the present paper. The tests were carried out at 550℃ under various cyclic freqencies (hold time) and load levels,and the fracture surfaces were examined by using a scanning electron microscope. It is shown that the fracture mode of creep-fatigue and the effect of cyclic loading on crack growth change with the growth of crack and the increase of net-section stress,and both are reversed when the net-section stress is up to the yield stress of material.When σn <σ0.2, cracking is predominantly cycle-dependent transgranular and cyclic loading accelerates creep crack growth, whereas when σm>σ0.2, the case is reversed. 关 键 词：CREEP-FATIGUE CRACK growth CYCLIC loading net-section STRESS INITIAL STRESS SUPERALLOY