复合轧制SM45钢板的组织性能

Microstructure and properties of clad rolling SM45 steel plate

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。

Heavy plates over 100 mm are hardly produced by continuous casting slab due to the restriction of reduction ra-tio.SM45 clad steel plate with thickness 260 mm was manufactured by clad rolling. Test methods,such as ultrasonic in-spection,cold bending,tensile,impact and hardness,were utilized to test the combination degree and mechanical proper-ties. 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.