Hardness optimization of gas nitriding layer on 40CrNiMoA steel

By analyzing the effects of matrix hardness,tempered martensite quantity,nitriding temperature,nitrogen potential value,and gas exchange rate on nitriding performance of 40CrNiMoA steel,the study shows that the depth of the hardened layer/498HV1 increases with the increase of matrix hardness,tempering martensite quantity,decreasing nitriding temperature,and increasing nitrogen potential value and gas exchange rate.Gas nitriding of 40CrNiMoA steel can achieve a surface hardness of 600HV1 to 635HV1,while meeting the technical requirements of 498HV1 at a depth of 0.52mm.