Analysis and Control on Fracture of 20Mn2A High Tensile Steel for Round Link Chain  

作　　者：CAO Shu-wei 1,2,KANG Yong-lin 1,3,ZHAO Xian-ping 2,YANG Chang-chun 1 (1.School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China 2.Technology Center of Anyang Iron & Steel Group Co.,Ltd.,Anyang 455004,Henan,China 3.State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China) 

出　　处：《Journal of Iron and Steel Research International》2011年第S1期898-902,共5页

摘　　要：Based on the phenomenon of brittle fracture occurred during tensile test for 20Mn2A high strength circular chain used in coal mines,the fracture property is regarded as intercrystalline brittle one after macroscope observation and metallographic examination.It is analysed that the intercrystalline brittle fracture is due to high tempering temperature and limited processing site where final products are piled together after heat treatment,which lead to a lower cooling rate of internal chain,with Si,Mn and P etc elements segregating and enriching in the austenite grain boundary and forming high tempering brittleness.After these circular chains are tempered again for one hour at 670℃,and oil-cooled rapidly,due to the reversibility of high temper brittleness for structural alloy steel,the high temper brittleness can be eliminated and products are completely qualified after tensile inspection.Based on the phenomenon of brittle fracture occurred during tensile test for 20Mn2A high strength circular chain used in coal mines,the fracture property is regarded as intercrystalline brittle one after macroscope observation and metallographic examination.It is analysed that the intercrystalline brittle fracture is due to high tempering temperature and limited processing site where final products are piled together after heat treatment,which lead to a lower cooling rate of internal chain,with Si,Mn and P etc elements segregating and enriching in the austenite grain boundary and forming high tempering brittleness.After these circular chains are tempered again for one hour at 670℃,and oil-cooled rapidly,due to the reversibility of high temper brittleness for structural alloy steel,the high temper brittleness can be eliminated and products are completely qualified after tensile inspection.

关 键 词：high strength circular chain metallographic examination brittle fracture high tempering brittleness improvement measures 

分 类 号：TG142.14[一般工业技术—材料科学与工程]