Q345B特厚复合钢板开发

Research on the bonding properties of Q345B cladding heavy steel plate

为了开发150 mm以上的特厚钢板,采用Q345B连铸板坯,经过表面清理、真空焊接及室式炉加热、宽厚板轧机轧制的工艺生产200 mm特厚复合钢板;用探伤、拉伸、剪切及冷弯等试验检验其结合度和力学性能,利用光学显微镜和扫描电镜等分析特厚钢板的组织及拉伸断口。结果表明,采用该工艺生产的特厚复合钢板结合性良好,能够满足GB/T 7734—2004Ⅰ级探伤要求;结合部位组织和基体组织均为铁素体+珠光体组织;复合钢板的厚度方向断面收缩率达到35%以上。

In order to develop thick steel plate which is more than 150 mm thickness, the process which consists of the application of Q345B continuous casting slab with surface scarfing, vacuum welding and heat in chamber furnace, and the rolling by heavy steel plate mill was used to produce cladding heavy steel plate 200 mm in thickness. The bonding de- gree and mechanical properties were tested by flaw detection, tensile, shear and cold bending tests. Microstructure and the tensile fracture of heavy steel plate were analyzed by means of optical microscope and scanning electron microscope. Results show that the heavy steel plate produced by current process has good bonding properties and can satisfy the GB/T 7734--2004 I demand of flaw detection. Both the structure at bonding site and matrix structure are ferrite plus pearl- ite. The reduction on cross section in thickness direction reaches more than 35%.