2材料类型性能等级螺纹规格选用材料螺栓10.9SM12~M2420MntiBM27~M3035VB8.8SM12~M1635#M20~M2420MnTibM27~M3035VB螺母8H10HM12~M3035#垫圈35~45HRC12~3045#材料的化学成分材料C%Si%Mn%Ti%V%B%P%S%20MnTiB0.17~0.240.17~0.371.30~1.600.04~0.1000.0005~0.0035≤0.035≤0.03535VB0.31~0.370.17~0.370.50~0.9000.05~0.120.001~0.004≤0.04≤0.0435#0.32~0.400.17~0.370.50~0.90000≤0.035≤0.03545#0.42~0.500.17~0.370.50~0.90000≤0.035≤0.035)