毕业论文二 外文文献翻译.docVIP

学校代码： 10128 学 号： 2011209070aa 外文文献翻译 英文题目：Evaluation method of sensitivity of hydrogen embrittlement for high strength bolts 题目：高强度螺栓氢脆敏感性评价方法 学生姓名：a 学院: a 专业： 班级： 指导老师： 二零一五年五月十一日 Evaluation method of sensitivity of hydrogen embrittlement for high strength bolts Abstract In this study, high strength bolts of 1100 MP a and 1300 MP a grades were charged with hydrogen to measure the sensitivity of hydrogen embrittlement (HE). Different levels of stress conditions based on various tensile stress and strain rates were applied. The bolts were then examined to see whether cracks were formed on the screw threads. The tensile stress and strain rate condition producing the most number of cracks on the screw thread of the bolt was decided as the most suitable test condition for the measurement of sensitivity of HE. For 1100 MP a grade high strength bolts, the most cracks were observed at the tensile stress ratio of 0.85 (load of 80 kN) and strain rate of 1.6
10E?5/s, while for 1300 MP a grades, the most cracks were observed at tensile stress ratio 0.87 (load of 100 kN) and strain rate of1.6
10E?5/s. No cracks were found on the screw threads of bolt when the strain rate was increased over8.3
10E?4/s. 1. Introduction It is widely known that as the strength of a bolt increases, it becomes more sensitive to hydrogen related problems, thus limit-ing its application. Mechanical properties, such as a reduction area of ductile fracture, deteriorate drastically when hydrogen is introduced into steel. Especially, the higher the strength of steel,the more likely it is to cause the deterioration of mechanical properties by hydrogen, i.e. delayed fracture by hydrogen embrit-tlement (HE) [1,2]. Weld metal and heat-affected zones show clear de gradation of mechanical properties by hydroge