Effect of tempering on microstructure and mechanical properties of SAE 1022 and SAE 10B21

• Main Authors: Pei-yu Huang, 黃珮瑜
• Other Authors: Dong-yih Lin
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/k9r9k9

碩士 === 國立高雄大學 === 化學工程及材料工程學系碩士班 === 103 === Taiwan is known for the "Kingdom of supplying screw", fastener industry continues for advancement every year from Y2006 to Y2015. But before the fastener products exports to other countries, it must have good quality. And this dissertation used the basic fastener material SAE 1022 and SAE 10B21 to experiment on torque, bending angle, hardness, carburizing depth and microstructure and etc. by tempering heat treatment with different temperature. In this study, adding boron in steel did not have obvious effect for torque value. It increased the bending angle from 28 % to 450 %, and the proportion of the toughness region of torque broken surface had improved evidently from 29.88% to 112.07%. Regarding the surface hardness decreased from 1.27 % to 26.43 %, but the core hardness was increased slightly to 3.05 %. And effective carburizing depth can be decreased from 0.11 % to 16.16 %. The experimental results was that after adding the boron in steel material, it could significantly improve the material properties of the bending angle and toughness, but the surface hardness and carburizing depth could be lower.