摘要
本文对热处理制度、介质成分及 pH值三种影响因素对GC-4(40CrMnSiMoVA)钢的腐蚀疲劳(CF)裂纹扩展速率(da/dN)_(CF)与应力腐蚀开裂(SCC)裂纹扩展速率(da/dt)_(SCC)的影响进行了对比研究。结果表明,这些因素对(da/dN)_(CF) 和(da/dt)_(SCC)有着不同的影响规律.(da/dN)_(CF)和(da/dt)_(SCC)均随σ_s的提高而提高,但(da/dN)_(CF)提高的幅度远小于(da/dt)_(SCC)提高的幅度.蒸馏水中的(da/dt)_(SCC)略大于3.5%NaCl溶液中的(da/dt)_(SCC),但蒸馏水中的(da/dN)_(CF)却远小于3.5%NaCl溶液中的(da/dN)_(CF).在 3.5%NaClI溶液中,随pH值增加,(da/dN)_(CF)下降,(da/dt)_(SCC)却增加.本文分别从裂尖材料的循环软化与硬化、裂纹闭合及闭塞电池效应等方面对上述现象进行了解释。
Comparative investigations were ca1ricd cut of tLe efItct of Leat 1reatment regimes for GC--4 steel, 40CrMnSiMoVA, on its c1ack p1opagating ratcs, from corrosion fatigue, (da/dN)..' or stress cor1osion crackirg, (do/dt),.,', in mcdia with various constituents and VH va1ues. Both (da/dN).. 8'r d (do/dt),.. acce!cra1e wi1h tbe increase of yieId stress of the steel, yet the fOraner js far 1ess tLan 1Le l8tcr. ]n ccmparison with mcdia, tLe (do/dt),,. in distil1td water is sligLt1y grca1cr 1Lan tbat in 3.5% NaCl solution, and tLe (dQ/dN)., in distil1cd water is far less ttan tkat in 3.5% NaCl solution. With the pH value increasing in 3.5% NLCl ao1ution, 1le (do/dN). F lQwerS down and the (da/dt),.. specds up. An xplahation was a1Eo r1oroltd witb concept of the cyclic bardening and softeniDg at crack tip, as we1l as the crack c1osure and occluded ceU effect.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
1991年第6期B403-B409,共7页
Acta Metallurgica Sinica
关键词
GC-4钢
腐蚀
疲劳
裂纹
应力
crack propagating rate
corrosion fatigue
stress corrosion cracking, heat treatment
pH value