为研究微合金钢第Ⅲ脆性区形成机理及其影响因素，控制连铸坯的表面裂纹，采用Gleeble热力模拟机测定了 S355微合金钢在不同温度下的抗拉强度及断面收缩率。使用扫描电镜对拉伸断口进行观察分析，同时采用透射电镜对析出物进行观察分析。在此基础上对拉伸试样进行金相实验，对第二相析出进行热力学计算，分析了组织状态及第二相析出规律对脆性区的影响。结果表明，在第Ⅲ脆性区(660~850℃)内，拉伸断口呈冰糖状，韧窝较浅，形貌表现为沿晶脆性断裂。铁素体网膜沿奥氏体晶界优先析出、第二相沿晶界析出是第Ⅲ脆性区形成的主要原因。
In order to study formation mechanism of brittle zone III and control the surface cracks of continuous casting slab,the tensile strength and reduction area of S3 5 5 microalloyed steel at different deformation tempera-tures were studied by Gleeble thermal simulation machine.Tensile fracture was observed by scanning electron mi-croscopy,and transmission electron microscopy was used to analyze the precipitates distribution.The influence of microstructure shape and precipitation behavior on the brittle zone III have been studied by metallographic experi-ment and second-phase thermodynamic calculation.The results show that brittle zone III of tested steel is about 660-850℃.In the brittle zone,the hot tensile fracture shows small sugar surface and shallow dimple,which is typical intergranular embrittlement fracture.Proeutectoid film-like ferrite formed along the austenite grain bounda-ry,second-phase precipitated along the grain boundary are the two main reasons for formation of brittle zone III.
参考文献
| [1] | 姚书芳;徐李军.连铸板坯内部裂纹的成因及防止措施[J].钢铁,2010(12):95-99. |
| [2] | 马玉喜;段小林;刘静;郭斌;陶军晖;杜明.800 Mpa级含Ti高强钢铸坯断裂的原因[J].钢铁研究学报,2016(2):51-56. |
| [3] | 孙胜英;马永昌.SS400连铸坯高温热塑性分析[J].理化检验-物理分册,2014(4):266-267,298. |
| [4] | 陈文满;陈登福;黄丽;廖明.热轧硅钢高温力学性能研究[J].材料导报,2008(z1):426-428. |
| [5] | 郭海滨;左秀荣;张新理;姬颍伦;洪良.奥氏体化温度对奥氏体晶粒度及第二相固溶的影响[J].钢铁研究学报,2016(2):63-68. |
| [6] | B. Mintz;J. R. Banerjee;K. M. Banks.Regression equation for Ar_3 temperature for coarse grained as cast steels[J].Ironmaking & Steelmaking: Products and applications,20113(3):197-203. |
| [7] | 闫永其;崔衡;王征;赵爱民.含P高强IF钢的高温力学性能[J].材料研究学报,2015(8):602-606. |
| [8] | 高碳钢连铸板坯高温力学性能[J].北京科技大学学报,2005(05):545-548. |
| [9] | Barrie MINTZ.The Influence of Composition on the Hat Ductility of Steels and to the Problem of Transverse Cracking[J].ISIJ International,19999(9):833-855. |
| [10] | 徐蕊;孙彦辉;曾亚南;蔡开科.含Nb-Ti微合金钢第三脆性区铸坯缺陷[J].钢铁研究学报,2014(11):45-50. |
| [11] | 朱新华;朱立光;魏巍;董亮.Q195钢连铸坯高温力学性能研究[J].铸造技术,2013(5):544-546. |
| [12] | 唐晶;赖朝彬;陈英俊;孙乐飞;刘敏.E690海洋平台用钢的高温塑性研究[J].有色金属科学与工程,2015(4):58-61. |
| [13] | 李鸿美;曹建春;孙力军;周晓龙;何寒;米永峰.含铌微合金钢碳氮化物析出行为研究的现状及发展[J].材料导报,2010(17):84-87. |
| [14] | 马范军;文光华;唐萍;韩靖.含铌、钒、钛微合金钢连铸坯角部横裂纹研究现状[J].材料导报,2010(5):89-91,95. |
| [15] | 刘青;张建峰;张晓峰;卢新春;谢飞鸣;李红卫;刘孝山;张路莎.合金弹簧钢连铸坯高温力学性能分析[J].重庆大学学报,2013(5):44-50. |
| [16] | Stanislaw Zajac.Precipitation of Microalloy Carbo-nitrides Prior, during and after gamma/alpha Transformation[J].Materials Science Forum,20050(0):75-86. |
| [17] | June-Soo Park;Dong-Hyun Kim;Youna-Kook Lee.NbC Precipitation Kinetics during and after γ/a Transformation of a Nb Microailoyed Steel[J].Materials Science Forum,20075(5):4191-4195. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%