在武钢CSP生产线上，通过控轧控冷工艺生产低成本低碳CMn钢薄板。结果表明，生产出的薄板屈服强度大于313MPa，抗拉强度高于400MPa，伸长率超过37%，屈强比低于083，冷弯性能良好，满足塑性要求，但常出现表面裂纹。从热力学角度分析出尺寸大于83nm的硬脆粒子会引起裂纹，而钢中析出物尺寸约为30nm，不足以引起裂纹。金相和扫描电镜观察到裂纹周围有混晶现象，计算表明混晶造成的应力集中约为120MPa，大于F3轧制时钢带的强度，容易导致裂纹的产生。经提高开轧温度、降低终轧温度及卷取温度后，表面裂纹发生率从367%降低到了134%。
CMn thin slab steel had been produced at low cost by controlled rolling and cooling method in CSP factory of Wuhan Iron and Steel (Group) Corporation. The mechanical properties of tested steels were measured as: the yield strength of 313MPa, the tensile strength of ≥400MPa and the elongation of ≥37%. The YR was below 083 and ductility was good. However, the surface cracks often appeared. The particles with size of 83nm can cause cracks by thermodynamics analysis, while the particles in the experimental steel was about 30nm, which cannot bring about cracks. Meanwhile, mixedgrain was observed in the vicinity of the crack. The stress concentration calculated to be 120MPa, which was more than the strength of the steel rolled by F3 pass, may probably lead to crack. The rate of surfacial crack reduces from 367% to 134% with higher start rolling temperture as well as lower finishing rolling temperture and coiling temperature.
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