摘要
用慢应变速率技术研究了敏化的304不锈钢在氧饱和的NaCl溶液中的应力腐蚀断裂(SCC)行为以及浓度、温度和电位的影响。结果表明,在90℃1000ppmNaCl溶液中,在5.5×10^(-6)s^(-1)应变速率下,电位大于-0.5V(相对于SCE,下同)有应力腐蚀敏感性。随着应变速率提高、浓度减小或温度降低,断裂电位范围移向较正的电位(-0.2V以上)。在较慢的应变速率下,在-0.5～-0.2V产生单裂纹;高于-0.2V对于所用的两种应变速率都产生多裂纹;低于-0.6V未发现裂纹。该体系的自腐蚀电位在-0.25V附近,处于SCC敏感区。恒电位下动态应变试验中电流增量与平均裂纹速度在双对数座标上呈正比关系,表明该体系的沿晶SCC本质上受溶解控制。
Stress corrosion cracking(SCC) of sensitized 304 stainless steel in oxygenated chloride solutions and the effects of the concentration of NaCl solution,temperature and potentials have been studied by means of the slow strain rate technique.The results show that susceptibility to SCC is markedly for the alloy in 1000ppm NaCl,.at 90℃,the control potential above-0.5V(SCE) and initial strain rate of 5.5×10-6s-1 There is obviously a consistent shift of the potential at which SCC is initiated to higher values(above-0.2V) as the temperature and the concentration of NaCl solution are reduced.That the intergranular cracking is essentially dissolution controlled seems an inevitable conclusion and that below about-0.3V(SCE),where single cracks formed,cracking probably is initiated from a pit with-in which the reactions are the same as resulted in multiple cracking at higher potentials.No cracking was found below-0.6V(SCE),So the system,whose free corrosion potential is about-0.25V(SCE),is susceptible to SCC.
出处
《北京航空航天大学学报》
EI
CAS
CSCD
北大核心
1990年第4期96-100,共5页
Journal of Beijing University of Aeronautics and Astronautics
关键词
不锈钢
应力腐蚀断裂
慢应变速率
stress corrosion cracking,slow strain rate technique,stainless steel.
