Application of Retaining Ring to Environmental Hydrogen Embrittlement Test in Pickling Process of Steel

• Main Authors: Ching Hung Chen, 陳勁宏
• Other Authors: 范光堯
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/374yd5

碩士 === 國立中興大學 === 機械工程學系所 === 99 === Hydrogen embrittlement is an environmental damage which affects the quality of products. If the factors causing hydrogen embrittlement af-fected by environment during pickling process could be fixed, the envi-ronment in the process would be improved and thus the loss would be re-duced. Before that, a method to check pickling environment without im-mersing products should be well defined. Thus, in this study, a retaining ring was applied to examine the pick-ling environment on hydrogen embrittlement. By setting the size, hardness, and opening of the ring and the pre-immersion duration prior to pickling as the factors for Design of Experiments, a series of experiments with dif-ferent setting levels for each factor were executed to observe the number of broken retaining rings pickled in different concentrations of acid with-out any additions, respectively. Among the experiment results, the most suitable level of each factor to sift a pickling environment was sought by setting various nominals for each concentration of acid according Taguchi method. As a result, a ring of type 5 having hardness between HV 590 and 620 clamped onto a round rod in diameter 5 mm and waiting for 30 min-utes before immersing into the pickling liquid was found as the most suit-able condition for checking the environment for hydrogen embrittlement in the pickling process by using regression analysis, additionally, which matched the experiment results.