Q345B钢板冷弯开裂原因分析及改进措施
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摘要
通过采用宏观检验、化学成分分析、力学性能检测以及金相检测等方法对Q345B钢板冷弯开裂样品进行分析。结果表明,冷弯开裂的主要原因是硫化物夹杂过多。硫化物夹杂在冷弯过程中易碎裂或与基体组织分离产生孔隙并成为裂纹源,且硫化物夹杂易导致轧钢过程中出现带状组织,而严重的带状组织也加剧了宏观裂纹的形成。提出了采用铁水预处理脱硫、增加吹氩强度、保证吹氩时间、增大轧制冷却速度等方法改善Q345B钢板的塑性和韧性,降低冷弯开裂的几率的建议。
The cold bending cracking samples of Q345 B steel plate were analyzed by macroscopical examination, chemical composition analysis, mechanical property test and metallographic examination.The results show that the main reason of cold bending cracking is too many sulphide inclusions. The sulphide inclusions are prone to break or separate from the matrix to form pores and become the source of cracks during cold bending, and the inclusion of sulfides can lead to the appearance of banded structures during rolling, and the formation of macroscopic cracks is aggravated by the serious banded structure. Some suggestions are put forward to improve the ductility and toughness of Q345 B steel plate and reduce the probability of cold bending cracking by means of desulphurizing pretreatment of molten iron, increasing argon blowing strength, ensuring argon blowing time and increasing rolling cooling rate.
The cold bending cracking samples of Q345 B steel plate were analyzed by macroscopical examination, chemical composition analysis, mechanical property test and metallographic examination.The results show that the main reason of cold bending cracking is too many sulphide inclusions. The sulphide inclusions are prone to break or separate from the matrix to form pores and become the source of cracks during cold bending, and the inclusion of sulfides can lead to the appearance of banded structures during rolling, and the formation of macroscopic cracks is aggravated by the serious banded structure. Some suggestions are put forward to improve the ductility and toughness of Q345 B steel plate and reduce the probability of cold bending cracking by means of desulphurizing pretreatment of molten iron, increasing argon blowing strength, ensuring argon blowing time and increasing rolling cooling rate.
引文
[1]王志军,王树胜.Q345B钢板冷弯开裂原因分析与改进措施[J].山西冶金,2012,35(4):59-60.
[2]孙贤文,柏卓明.低碳锰钢的带状组织及其对钢板冷弯性能的影响[J].电子显微学报,2004,23(4):447.
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[7]于洪彪.钢材带状组织的产生原因及消除方法[J].科技传播,2014(9):194.
[8]蔡珍,黄运华,张跃,等.冷却速度对铁素体-珠光体带状组织的影响机制[J].2012,24(6):25-30.
[9]刘富军,刘年富,廖卫团.带状组织对低碳微合金钢性能的影响及控制[J].南方金属,2011,(1):7-10.
[10]纪元,闵云峰,李鹏善,等.钢中带状组织及其研究现状[J].中国冶金,2016,26(4):1-8.
[2]孙贤文,柏卓明.低碳锰钢的带状组织及其对钢板冷弯性能的影响[J].电子显微学报,2004,23(4):447.
[3]申少华,刘国林.中厚钢板中的硫化物夹杂及其对冷弯性能的影响[J].宽厚板,2005,11(2):26-30.
[4]申少华,刘国林,韦弦,等.化学成分对中厚钢板冷弯性能的影响[J].河南冶金,2004,12(6):3-4.
[5]刘克俭,王祖宽,杨桂荣.钢中夹杂物的产生及其形态控制[J].河北理工学院学报,2001,23(1):21-23.
[6]朱伟华,王玲玲.低碳合金钢中带状组织的形成机理和消减方法[J].莱钢科技,2007,(1):14.
[7]于洪彪.钢材带状组织的产生原因及消除方法[J].科技传播,2014(9):194.
[8]蔡珍,黄运华,张跃,等.冷却速度对铁素体-珠光体带状组织的影响机制[J].2012,24(6):25-30.
[9]刘富军,刘年富,廖卫团.带状组织对低碳微合金钢性能的影响及控制[J].南方金属,2011,(1):7-10.
[10]纪元,闵云峰,李鹏善,等.钢中带状组织及其研究现状[J].中国冶金,2016,26(4):1-8.