牌号化学成分%CSiMnPSNiCrCuMo其他450.42-0.500.17-0.370.50-0.80≤0.35≤0.35≤0.25≤0.25≤0.20--27SiMn0.24-0.321.10-1.401.10-1.40≤0.35≤0.35≤0.25≤0.25≤0.20≤0.15-牌号机械性能抗拉强度MPa屈服强度MPa延伸率%冲击功J硬度HBS45≥600≥355≥16≥39≤19727SiMn≥980≥835≥12≥39≤217)