›› 2016, Vol. 32 ›› Issue (1): 70-73.

• 凝固与浇铸 • 上一篇    下一篇

钛铌高强钢板坯低倍裂纹产生机理分析

刘学华1,舒宏富2,程锁平3,仇圣桃4,干勇5   

  1. 1. 马钢
    2. 马鞍山钢铁股份有限公司技术中心
    3. 马鞍山钢铁股份有限公司
    4. 钢铁研究总院连铸技术国家工程研究中心
    5. 钢铁研究总院 国家连铸技术中心
  • 收稿日期:2015-08-04 修回日期:2015-09-16 接受日期:1900-01-01 出版日期:2016-02-05 发布日期:2016-02-29
  • 通讯作者: 刘学华 E-mail:15755519332@163.com

Mechanism analysis on macro-etching crack of high strength steel slab containing titanium and niobium

  • Received:2015-08-04 Revised:2015-09-16 Accepted:1900-01-01 Online:2016-02-05 Published:2016-02-29

摘要: 为揭示钛铌高强钢板坯低倍裂纹的产生机理,采用低倍酸洗、金相分析和GLEEBLE热模拟试验等方法,研究了板坯低倍裂纹形貌及该钢种的连续冷却转变特性,从温度变化及相变角度探讨了板坯低倍裂纹形成原因。结果表明, 板坯火焰切割后,距切割面30mm以内冷却速度可达5℃/s以上,高的冷却速度下铸坯产生了贝氏体、马氏体相变,在热应力和相变应力的共同作用下,导致了钛铌高强钢板坯低倍裂纹。

关键词: 钛铌高强钢, 板坯, 相变, 裂纹

Abstract: In order to explore the forming mechanism of crack on high strength slab containing titanium and niobium, the morphology of crack was revealed by macro-etching, the microstructure of slab and crack fractograph were examined by metallographic analysis and the characteristic of continuous cooling transformation was tested based on the thermal expansion method via GLEEBLE-2000. Consequently forming reason of macro-etching crack on high strength steel slab containing titanium and niobium was elucidated from aspects of temperature variation and phase transformation. The results showed that cooling rate of the slab could reach as high as 5℃/s within the range of 30mm from torch cutting plane after torch cutting; high cooling rate made Bainitic and Martensitic phase transformation taking place on the slab; and the combination of stress caused by the high cooling rate and the phase transformation led to the severe macro-etching cracks on the high strength slab bearing titanium and niobium.

Key words: high strength steel containing titanium and niobium, slab, phase transformation, crack