CSP酸洗钢SAPH370的冷却工艺优化

Optimization of Cooling Process for SAPH370 Steel Made by CSP

屈强比偏高是CSP产品的共性问题。为降低CSP酸洗钢SAPH370的屈强比,采用正交化试验设计,研究了两段冷却工艺参数终轧温度、空冷起始温度和卷取温度对屈强比的影响。对试验结果进行统计,并利用光学显微镜分析了不同工艺条件下SAPH370钢的相组成和晶粒尺寸。研究结果表明,空冷起始温度和卷取温度对屈强比的影响显著。空冷起始温度由740℃提高到760℃,可降低屈强比0.017;卷取温度由500℃提高到560℃,可降低屈强比0.015;而终轧温度对屈强比的影响不太明显,终轧温度由860℃提高到880℃,屈强比仅降低0.005。采用两段冷却工艺,通过调整空冷起始温度和卷取温度可有效降低酸洗钢SAPH370的屈强比。

High yield ratio was a common problem for products made by CSP process.To reduce the yield ratio of SAPH370 steel,based on orthogonal experiment,the effect of finish rolling temperature（FT7）,air-cooling temperature（ACT） and coiling temperature（CT） on yield ratio were investigated by two-stage cooling process,the statistical technique was used to analyze the test results,and optical microscope was employed to analyze the grain size and second phase of SAPH370 steel under different cooling rate.The results show that ACT and CT have obvious effect on the yield ratio,the yield ratio decreases 0.017 with ACT increased from 740 to 760 ℃,and the yield ratio decreases 0.015 with CT increased from 500 to 560 ℃;while the effect of FT7 on yield ratio is not obvious,when FT7 increases from 860 to 880 ℃,the yield ratio decreases only 0.005.In a word,the yield ratio of SAPH370 steel could be decreased observably by using two-stage cooling process and optimizing the ACT and CT.