复合轧制SM45钢板的组织性能

 连铸坯直接轧制生产特厚钢板时，由于压缩比的限制，很难生产出厚度超过100 mm的高质量钢板。采用复合轧制工艺可生产出厚度为260 mm的SM45复合钢板。对钢板进行探伤、冷弯、拉伸、冲击及硬度等试验检验其结合度和力学性能。结果表明，复合轧制生产的SM45钢板结合度良好，未发现明显的缺陷存在。钢板复合界面与基体的强度均在600 MPa以上；Z]向试样的强度也达到600 MPa以上，断面收缩率在30%以上；冲击功在37 J以上。钢板不同位置处的基本组织都为铁素体与珠光体，但晶粒尺寸不同。复合界面处的组织为一条铁素体为主的带状组织，该组织的产生是由先共析铁素体导致的。

Microstructure and properties of clad rolling SM45 steel plate

Heavy plates over 100 mm are hardly produced by continuous casting slab due to the restriction of reduction ratio.SM45 clad steel plate with thickness 260 mm was manufactured by clad rolling. Test methods， such as ultrasonic inspection， cold bending， tensile， impact and hardness， were utilized to test the combination degree and mechanical properties. The results showed that SM45 plate manufactured by clad rolling combined well and had no obvious defection. Strengths of clad interface and base body were both above 600 MPa. Z] direction strengths were also above 600 MPa， and contraction of area were above 30%. Impact energy was above 37 J. The basic microstructure of SM45 steel plate was ferrite and pearlite， but the grain size was different in different locations. There was a ferrite belt in clad interface which formed because of the proeutectoid ferrite.