炼钢

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管线钢钙处理工艺优化

李 强,赵家七,蔡小锋,邹长东   

  1. (江苏省(沙钢)钢铁研究院,江苏 张家港 215625)
  • 接受日期:1900-01-01 出版日期:2019-10-05

Quality analysis of silicon-calcium wire and optimization of calcium treatment process for pipeline steel

  • Accepted:1900-01-01 Online:2019-10-05

摘要: 针对X80M钢成品板材中夹杂物导致探伤合格率低的问题,对其炼钢过程进行排查发现,钙处理使用的硅钙线中有效钙含量偏低。通过更换硅钙线种类以及优化钙处理工艺,钙处理时控制钢水中w(S)<25×10-6,将喂线速度由1.8m/s提高至2.5m/s,底吹流量由180~200L/min降低为120~150L/min,钢水中成品Ca质量分数控制在(13~25)×10-6,Al2O3夹杂均改性为低熔点铝酸钙夹杂,基本处于CaO-Al2O3-CaS三元相图中低熔点区,夹杂物尺寸均在50μm以下,X80M钢探伤合格率平均由94.60%提高至99.69%左右,保证了产品质量。

关键词: X80M, 探伤, 夹杂物, 钙处理

Abstract: In view of the low qualified flaw detection rate caused by X80M inclusions,the steelmaking process was investigated and found that the effective calcium content in the silicon-calcium wires used for calcium treatment was low. By changing the types of silicon-calcium wires and optimizing the process of calcium treatment,such as controlling w(S) below 25×10-6,increasing the feeding speed of silicon-calcium wires from 1.8 m/s to 2.5 m/s,reducing the bottom blowing flow rate from 180~200 L/min to 120~150 L/min,w(Ca) in molten steel was controlled at (13~25)×10-6,Al2O3 inclusions couuld be modified into calcium aluminate inclusions in the low melting point zone of CaO-Al2O3-CaS ternary Phase Diagram,and their sizes were all below 50μm. The qualification rate of flaw detection for X80M steel increased from 94.60% to 99.69% on average,which ensures the quality of products.

Key words: X80M, flaw detection, inclusion, calcium treatment