A 42CrMo large roller core forging was scrapped due to the discovery of circular cracks after quenching and tempering.Perform chemical composition,low magnification,and high magnification micro structure analysis on the crack source area,and quantitatively analyze the inclusions on the fracture surface using SEM and EDS.The results showed that multiple millimeter sized small precipitate aggregation areas were found at the crack source,which contained high contents of elements such as Cr,Mn,and Mo.These aggregated precipitates can disrupt the continuity of the material and generate significant local stress concentration during heat treatment,leading to the formation of initial cracks.By increasing the VD high vacuum time,improving the argon protection device during the pouring process,and increasing the proportion of risers,adjusting the heat treatment quenching water cooling system can control the risk of cracking in t he roller core during quenching and tempering.
关键词
造纸设备/辊芯锻件/调质开裂
Key words
papermaking equipment/roll core forgings/quenching and tempering cracking
维普
万方数据