天津聚源钢铁022-26801886耐大气腐蚀桥梁板钢化学成分（质量分数）/%牌号CSiMnNbVTiCrNiCuNAlMoQ345qNH≤0.110.15-0.51.1-1.50.01-0.10.01-0.10.006-0.030.4-0.70.3-0.40.25-0.5≤0.0080.015-0.05≤0.1Q370qNH≤0.15Q420qNH≤0.2Q460qNHQ500qNH0.45-0.70.3-.0450.25-0.55≤0.25Q550qNH)