Constant-load delayed fracture test of atmospherically corroded high strength steels
Constant-load delayed fracture test of atmospherically corroded high strength steels
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DOI：
10.1016/j.apsusc.2011.03.037
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发表时间：
2011-07
影响因子：
6.7
通讯作者：
E. Akiyama;Katsuhiro Matsukado;Songjie Li;K. Tsuzaki
中科院分区：
文献类型：
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作者：
E. Akiyama;Katsuhiro Matsukado;Songjie Li;K. Tsuzaki
对循环腐蚀试验和室外暴露后的高强度钢圆周切口圆钢试样进行恒载荷试验，结果表明，当环境中的氢含量 HE 超过延迟断裂临界氢含量 HC 时，会发生延迟断裂。在恒定负载测试期间，样品周围的湿度逐步增加以增加氢气进入。断裂后，将样品保持在湿度下足够长的时间以使样品中的氢均质化并通过热解吸分析获得更定量的氢含量。断裂试件的HE高于HC，未断裂试件的HE低于HC。这一结果证实了HC和HE之间的平衡决定了延迟断裂的发生，并且基于氢含量的延迟断裂敏感性评估是合理的。为了证明HE随着湿度的增加而增加，进行了电化学氢渗透测试。氢渗透电流密度尤其在98%RH下增加。测试还表明，氢进入随着 CCT 数的增加而增强。
Constant load tests of circumferentially notched round bar specimens of high strength steels after cyclic corrosion test and outdoor exposure have been performed to demonstrate that delayed fracture occurs when the hydrogen content from the environment, HE, exceeds the critical hydrogen content for delayed fracture, HC. During the constant load tests the humidity around the specimen was increased in stepwise manner to increase hydrogen entry. After fracture the specimen was kept at the humidity long enough to homogenize hydrogen in the specimen and to obtain more quantitative hydrogen content by thermal desorption analysis. HEof the fractured specimens was higher than HC, and HEof the specimens not fractured was lower than HC. This result confirms that the balance between HCand HEdetermines the occurrence of delayed fracture and that hydrogen-content-based evaluation of susceptibility to delayed fracture is reasonable. To certify the increase of HEwith increase in humidity, electrochemical hydrogen permeation test was carried out. The hydrogen permeation current density was increased especially at 98%RH. Enhancement of hydrogen entry with increase in CCT number was also shown by the test.