钛铌微合金钢连铸坯角部横裂纹敏感性

杨柳 ,李阳 ,薛正良 ,程常桂

钢铁研究学报 ›› 2018, Vol. 30 ›› Issue (10) : 807-815.

钢铁研究学报 ›› 2018, Vol. 30 ›› Issue (10) : 807-815. DOI: 10. 13228/j.boyuan.issn1001- 0963. 20180015
材料研究

钛铌微合金钢连铸坯角部横裂纹敏感性

  • 杨柳1,2,3,李阳1,2,薛正良1,2,程常桂1,2
作者信息 +

Corner transverse crack sensitivity of Ti- Nb micro- alloyed steel slabs during continuous casting

  • YANG Liu1,2,3,LI Yang1,2,XUE Zheng- liang1,2,CHENG Chang- gui1,2
Author information +
文章历史 +

摘要

为明确不同速度冷却时表面奥氏体的长大规律和在第Ⅲ脆性区的热塑性,用Gleeble- 3500热模拟机分别对钛铌微合金钢进行了奥氏体长大热模拟试验和第Ⅲ脆性区热拉伸试验。研究结果表明,当冷却速率小于5℃/s时,钛铌微合金钢铸坯表面容易形成粗大的(大于1mm)奥氏体晶粒;随着冷却速率的增大,奥氏体边界析出细小的Ti(C,N),能有效地钉扎限制奥氏体的长大。在热拉伸试验过程中,当冷却速率为1和5℃/s时,钛铌微合金钢铸坯在800℃热拉伸时断面收缩率仅为29. 7%和23. 0%,2种冷速下都伴随有70~200nm矩形或不规则形的(Ti,Nb)(C,N)和40~100nm针状的Nb(C,N)析出。铸坯角部振痕谷底处在高温低冷速下形成粗大奥氏体晶粒,并在第Ⅲ脆性区矫直,是导致钛铌微合金钢角部横裂纹敏感性高的主要原因。

Abstract

By Gleeble- 3500 thermal simulator, the simulation experiments of austenite grain growth and ductility in the third brittle zone on the surface slab were carried out respectively, which identified the growth regularity of austenite size and hot ductility under different cooling rates. The results show that the austenite “blown grains” (>1mm) with lower cooling rate (<5℃/s) are formed easily. The precipitates of fine Ti(C,N) around the austenite boundary could pin and limit the growth of austenite with the increase of cooling rate. In the thermal stretching experiment, reduction of area of Ti- Nb bearing mirco- alloyed steel slab at 800℃ respectively are only 29. 7% and 23. 0% with cooling rate of 1 and 5℃/s. Both precipitating rectangle or irregular (Ti,Nb)(C,N) precipitates with 70-200nm size and needlelike Nb(C,N) precipitates with 40-100nm. The formation of “blown grains” at the depths of oscillation marks with low cooling rate, and straightening in the third brittle zone are the major causes of high corner transverse crack sensitivity of Ti- Nb micro- alloyed steel slabs.

关键词

微合金钢 / 奥氏体尺寸 / 热塑性 / 碳氮化物 / 冷却速率

Key words

Micro-alloyed steel / Austenite size / Ductility / Carbonitride / Cooling rate

引用本文

导出引用
杨柳 ,李阳 ,薛正良 ,程常桂 . 钛铌微合金钢连铸坯角部横裂纹敏感性[J]. 钢铁研究学报, 2018, 30(10): 807-815 https://doi.org/10. 13228/j.boyuan.issn1001- 0963. 20180015
YANG Liu,,,LI Yang,,XUE Zheng- liang,,CHENG Chang- gui,. Corner transverse crack sensitivity of Ti- Nb micro- alloyed steel slabs during continuous casting[J]. Journal of Iron and Steel Research, 2018, 30(10): 807-815 https://doi.org/10. 13228/j.boyuan.issn1001- 0963. 20180015

参考文献

[1] 翁宇庆.超细晶钢—钢的组织细化理论与控制技术[M]. 冶金工业出版社,2003:290-292.
[2]Derda W, Wiedermann J.Some aspects of continuous casting of low carbon micro-alloyed steels with niobium and titanium[J].Archives of Metallurgy & Materials, 2012, 57(1):303-310
[3]Li Y, Wen G, Luo L, et al.Study of austenite grain size of micro-alloyed steel by simulating initial solidification during continuous casting[J].Ironmaking & Steelmaking, 2015, 42(1):41-48
[4]Dippenaar R, Bernhard C, Schider S, et al.Austenite grain growth and the surface quality of continuously cast steel[J].Metallurgical and Materials Transactions B, 2014, 45(2):409-418
[5]Li Y, Chen X, Liu K, et al.Reasonable temperature schedules for cold or hot charging of continuously cast steel slabs[J].Metallurgical and Materials Transactions A, 2013, 44(12):5354-5364
[6]Banks K M, Tuling A, Klinkenberg C, et al.Influence of Ti on hot ductility of Nb containing HSLA steels[J].Materials Science & Technology, 2011, 27(2):537-545
[7] Stock J.NbC and TiN precipitation in continously cast microalloyed steels[D]. Colorado University, 2014.
[8]Mustafa Merih Ar?kan.Hot ductility behavior of a peritectic steel during continuous casting[J].Metals, 2015, 5(2):986-999
[9]Rian Dippenaar, Suk-Chun Moon, Edward S Szekeres.Strand surface cracks - the role of abnormally large prior-austenite grains[J].Iron & Steel Technology, 2007, 4(7):105-115
[10]Yang Liu, Li Yang, Xue Zhengliang.Influence of Ti(C,N) precipitates on the austenite growth of micro-alloyed steels during continuous casting[J].China Foundry, 2017, 14(5):145-152
[11]I. Andersen, O. Grong.Analytical modelling of grain growth in metals and alloys in the presence of growing and dissolving precipitates-Ⅰ[J].Normal grain growth, 1995, 43(7):2673-2688
[12]Bernhard C, Reiter J, Presslinger H.A model for predicting the austenite grain size at the surface of continuously-cast slabs[J].Metallurgical and Materials Transactions B, 2008, 39(6):885-895
[13] 雍歧龙.钢铁材料中的第二相[M]. 冶金工业出版社,2006,357-392.
[14] 雍歧龙.钢铁材料中的第二相[M]. 冶金工业出版社,2006,172.
[15]Mintz B, Cowley A, Abushosha R.Importance of columnar grains in dictating hot ductility of steels[J].Materials Science and Technology, 2000, 16(1):1-5
[16]Mintz B.Influence of nitrogen on hot ductility of steels and its relationship to problem of transverse cracking[J].Ironmaking & Steelmaking, 2000, 27(5):343-347
[17]马玉喜,段小林,刘静.级含高强钢铸坯断裂的原因[J].钢铁研究学报, 2016, 28(2):51-56
[18] 马范军.微合金钢铸坯第二相析出行为及表层组织演变研究[D]. 重庆大学,2010.
[19] 李阳.亚包晶低合金高强度钢的初始凝固与固态相变行为研究[D]. 北京科技大学,2013.
[20]兰鹏,杜辰伟,陈培丽,等.微合金钢连铸表面横裂纹形成机理与控制技术研究现状[J].钢铁研究学报, 2017, 29(1):1-12

基金

中间包水口吹氩过程壁面氩气膜的形成与迁移行为研究;吹氩结晶器内氩气泡对液态保护渣传热及流动行为的影响

117

Accesses

0

Citation

Detail

段落导航
相关文章

/