大规格SCM440钢冷镦开裂原因分析及改进
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摘要
针对国内某用户在使用某公司的大规格中碳合金冷镦钢SCM440盘条生产12.9级高强内六角螺栓时出现螺栓头部开裂的不良情况,我们采用金相检验、能谱分析等手段对开裂试样进行了观察和分析。结果表明:冷镦开裂是由于盘条表面划伤、裂纹、折叠等表面质量缺陷所致。针对盘条表面存在的质量缺陷问题,通过优化炼钢保护渣性能、改善炼钢工艺、改造高线工艺设备、加强对高线导卫和导槽等工艺设备的监管检查和更换、增加头尾的剪切量,最终解决了盘条冷镦开裂的问题。
When a domestic customer uses our company's large-size medium-carbon alloy cold-rolled steel SCM440 wire rod to produce 12.9 high-strength hexagon socket bolts, the bolt head cracking occurs. To address this issue, we observed and analyzed the samples by using metallographic examination, energy spectrum analysis and other means. The results show that the cold head cracking is caused by surface quality defects such as scratches, cracks and folds on the wire rod surface. For the quality defects in the surface of the wire rod, we enhanced the performance of mold flux, improved the steelmaking process, optimized equipment for high speed wire, strengthened the supervision, checking and replacement of guard and guide channel, and increased the head and tail cutting length, and finally solved the problem of cold head cracking of the wire rod.
When a domestic customer uses our company's large-size medium-carbon alloy cold-rolled steel SCM440 wire rod to produce 12.9 high-strength hexagon socket bolts, the bolt head cracking occurs. To address this issue, we observed and analyzed the samples by using metallographic examination, energy spectrum analysis and other means. The results show that the cold head cracking is caused by surface quality defects such as scratches, cracks and folds on the wire rod surface. For the quality defects in the surface of the wire rod, we enhanced the performance of mold flux, improved the steelmaking process, optimized equipment for high speed wire, strengthened the supervision, checking and replacement of guard and guide channel, and increased the head and tail cutting length, and finally solved the problem of cold head cracking of the wire rod.
引文
[1]钱立和.国内外冷镦钢进展[J].轧钢, 2000(4):25-29.
[2]和前进,潘金焕,姜均普,等.影响湘钢冷镦钢质量的主要因素[J].钢铁, 2003(1):25-28.
[3]张步海,于同仁.冷镦钢线材表面裂纹形成原因分析[J].金属制品, 2004(3):23-26.
[4]李慧峰.冷镦钢产品顶锻开裂的机理分析及应用[J].太钢科技, 2005(1):34-37.
[5]帅习元,郑元峰.冷镦钢表面一种特殊线状缺陷形成原因分析[J].物理测试, 2007(4):32-35.
[6]王有铭.钢材的轧制控制和控制冷却[M].北京:冶金工业出版社, 1995.
[2]和前进,潘金焕,姜均普,等.影响湘钢冷镦钢质量的主要因素[J].钢铁, 2003(1):25-28.
[3]张步海,于同仁.冷镦钢线材表面裂纹形成原因分析[J].金属制品, 2004(3):23-26.
[4]李慧峰.冷镦钢产品顶锻开裂的机理分析及应用[J].太钢科技, 2005(1):34-37.
[5]帅习元,郑元峰.冷镦钢表面一种特殊线状缺陷形成原因分析[J].物理测试, 2007(4):32-35.
[6]王有铭.钢材的轧制控制和控制冷却[M].北京:冶金工业出版社, 1995.