高强度低碳贝氏体钢管的研制及在东海大桥的应用

Research and Development of High Strength Low Carbon Bainitic Steel Pipe & Its Application in Donghai Bridge

介绍了采用高强度低碳贝氏体钢、通过调整冷弯成型及焊接工艺参数来实现东海大桥护栏用直缝焊管的生产情况。对原料成分和力学性能对冷弯成型工艺参数的影响，轧制线速度和焊接高频功率对焊接质量的影响等进行了试验研究。结果表明：当焊接高频功率为295～300kW，线速度为9～17m／min时，用MDB400钢生产的φ114mm×6mm钢管，其焊缝组织为贝氏体＋细晶铁素体＋珠光体组织，且含碳量低，冷裂纹敏感性小，各项指标均符合产品标准要求。

It introduces production condition of longitudinal welded pipe used for guardrail of Donghai bridge through adjusting cold bending forming and welding procedure parameters with high strength low carbon bainitic steel and test to study the influence of raw material composition and mechanical properties to process parameters of cold bending forming,as well as influence of rolling linear speed and welding high-frequency power to welding quality,etc..The results shows that the structure of weld consists of bainitic,fine ferrite and pearlite when steel pipe of OD 114 mm×6 mm is produced by MDB400 steel under the welding high frequency power of 295-300 kW and linear velocity of 9~17 m/min and due to lower carbon content and smaller cold crack sensitivity,all indexes conform to requirements of product standard.