摘要
通过对在空气中与阴极渗氢情况下２．２５Ｃｒ－１Ｍｏ钢的短裂纹扩展研究，发现在氢的作用下，ΔＪｔｈ约为３６０×１０－６ＭＮ／ｍ，较空气中约低２００×１０－６ＭＮ／ｍ，ｄａ／ｄＮ－ΔＪ关系与空气中相比左移，且随ΔＪ区间不同，左移量不也不同。断口分析表明，在疲劳裂纹扩展的三个阶段，氢原子与交变力动态地起着协同作用。在≈１０００×１０－６ＭＮ／ｍ＜ΔＪ＜≈１２００×１０－６ＭＮ／ｍ内氢原子对裂纹扩展影响不明显可解释为：氢原子在局部晶界的偏聚导致应力过分集中而产生穿晶裂纹后应力缓解的结果。
Abstract An investigation made on the short crack propagational behaviours of 2.25 Cr 1Mo steel tested both in air and hydrogen obtained from cathodic polarization indicates that under the effect of hydrogen, Δ J th is approximately 360×10 -6 MN/m, and about 200×10 -6 MN/m lower than that obtained in air. The relationship between crack propagation rate da/d N and Δ J parameter in hydrogen moves to leftside to different extents with different Δ J range. Fracture analysis reveals different combination effects between hydrogen and applied force with different Δ J ranges. Not much influence, however, has been found in a specific Δ J range between ≈1000×10 -6 MN/m and ≈1200×10 -6 MN/m. It seems to be due to stress releasing after transcrystalline propagation resulting from hydrogen built up in a local grain boundary, which causes excess stress concentration.
出处
《机械工程材料》
CAS
CSCD
北大核心
1999年第1期15-17,35,共4页
Materials For Mechanical Engineering
