17-4PH不锈钢的析氢行为

Hydrogen Evolution of 17-4PH Stainless Steels

采用电化学测试的方法评价了两种强度的17-4PH不锈钢在海水中的阴极极化行为;采用充氢试验研究了两种强度的17-4PH不锈钢在-1.1V(SCE,下同)电位下阴极极化15d后的含氢量;采用慢应变速率试验研究了两种强度17-4PH不锈钢在充氢后的氢脆系数。结果表明:两种强度的17-4PH不锈钢在海水中的析氢转变电位均在-0.90V左右;低强度不锈钢的氢质量分数约为2.55×10^(-4)%,而高强度不锈钢的氢质量分数则高达6.84×10^(-4)%;试样充氢后,高强度不锈钢的脆性明显增加,而低强度不锈钢的脆性增加不明显,高强度不锈钢的氢脆系数远超过25%,此时材料已存在氢脆危险,而低强度不锈钢的氢脆系数约为18%左右,尚处于氢脆安全区。

The hydrogen evolution transforming potential and current density of hydrogen evolution at-1.10 V（vs.SCE,the same below）polarization potential of 17-4PH stainless steels with two distinguishing strength were studied using electrochemical test method.Hydrogen charging test was used to study the hydrogen contents of the alloys after 15 days of hydrogen charging at-1.1Vpolarization potential.The slow strain rate tests were used to evaluate the hydrogen embrittlement susceptibility of 17-4PH alloys with or without hydrogen charging.The results show that the hydrogen evolution transformed potentials of both 17-4PH stainless steels in seawater were about-0.90 V.The low strength 17-4PH strainless steel had a hydrogen content of only 2.55×10-4 mass%,while the high strength stainless steel had a hydrogen content as high as 6.84×10-4 mass%.The strainless steel with high strength showed a significant increase in brittleness after hydrogen charging,while the change in low-strength stainless steel was much smaller.The high strength stainless steel had a hydrogen embrittlement coefficient more than25%,which means the steel is among the risky range of hydrogen embrittlement;while the low strength stainless steel had a hydrogen embrittlement coefficient about 18%,which means the steel is in riskless range of hydrogen embrittlement.