Abstract： The nonquenched steel 18Mn2SiMo has high strength and toughness when it is normalized at 920 ℃ and tempered at 300 ℃. However, during the impact test of Vtype notch of sample by broaching machine at -40 ℃, the toughness cannot meet the technical requirements. The difference of room temperature impact and low temperature impact of Vtype notches produced by wireelectrode cutting and broaching were studied. The reason of lower impact value for broaching notch at low temperature was analyzed, and the method to improve the low temperature impact value was proposed. This study provided reference for improving the low temperature impact toughness proptery of 18Mn2SiMo steel.
2022, Vol. 40 
