Abstract:Microstructure and texture evolution of low-carbon Cr-Mo deep drawing dual-phase steel were investigated by using microstructure observation, TEM and XRD. The results show that, the finish-rolling process conducted in austenite no-recrystallization zone promoted the formation of {112}〈111〉 component. The intensity of {001}〈110〉,{112}〈110〉 and {223}〈110〉 orientations were steadily enhanced during cold rolling.The formation of sharper 〈111〉//ND, {554}〈225〉 and {332}〈113〉 textures during annealing was favorable to improve the deep draw-ability of dual-phase steel. When intercritical annealed at 820℃ and 860℃, the intensity of γ-fibre was slightly different. The difference of intensity between {111}〈110〉 and {111}〈112〉 texture tended to increase at high-temperature annealing, causing by the solution-carbon of bainite and the variant selection from austenite to bainite. The high-temperature coiling process induced precipitation of Mo-based carbide in hot-rolled strips, and re-dissolution during the holding stage in annealing process, which not only facilitated the formation of recrystallization textures, but also improved the second phase transformation.
[1] 康永林. 新一代汽车用先进高强钢的成形与应用[J]. 钢铁,2010,45(8):1-6.[2] HAN S H,CHOI S H,CHOI J K,et al. Effect of hot-rolling processing on texture and r-value of annealed dual-phase steels[J]. Materials Science and Engineering:A,2010,527(7-8):1686-1694.[3] HUTCHINSON W B. Development and control of annealing textures in low-carbon steels[J]. International Materials Reviews,1984,29(1):25-42.[4] 赵骧,関史江,伊藤邦夫,等. 高纯超低碳深冲钢板的固溶碳含量对再结晶γ织构的影响[J]. 金属学报,1995,31(6):262-265.[5] HU H. Studies on the development of high-strength dual-phase steel sheets with high rm values[J]. Metallurgical and Materials Transactions A,1982,13(7):1257-1262.[6] 马鸣图,吴宝荣. 双相钢的物理与冶金[M].2版.北京:冶金工业出版社,2009.[7] KANG J Y,LEE H C,HAN S H. Effect of Al and Mo on the textures and microstructures of dual phase steels[J]. Materials Science and Engineering:A,2011,530(15):183-190.[8] YOSHIDA H,OKUDA K,KAWABE H,et al. Effect of niobium addition on the texture formation of high strength cold-rolled low carbon steel sheets[J].Materials Science Forum,2007,558-559:425-430.[9] RAY R K,JONAS J J,BUTRON-GUILLEN M P,et al. Transformation textures in steels[J]. ISIJ International,1994,34(12):927-942.[10] RAY R K,JONAS J J. Cold rolling and annealing textures in low carbon and extra low carbon steel[J]. International Materials Reviews,1994,39(4):129-172.[11] RAY R K. Orientation distribution function analysis of texture in a dual-phase steel[J]. Materials Science and Engineering:A,1986,77:169-174.[12] BUTRON-GUILLEN M P,JONAS J J,RAY R K. Effect of austenite pancaking on texture formation in a plain carbon and a Nb microalloyed steel[J]. Acta Metallurgica et Materialia,1994,42(11):3615-3627.[13] INAGAKI H. Fundamental aspect of texture formation in low carbon steel[J]. ISIJ International,1994,34(4):313-321.[14] KANG J Y,BACROIX B,REGLE H,et al. Effect of deformation mode and grain orientation on misorientation development in a body-centered cubic steel[J]. Acta Materialia,2007,55(15):4935-4946.[15] NAGATAKI Y,HOSOYA Y. Origin of the recrystallization texture formation in an interstitial free steel[J]. ISIJ International,1996,36(4):451-460.[16] 杨平,李志超,毛卫民,等. 钢中{111}〈112〉再结晶织构的形成[J]. 材料热处理学报,2009,30(3):46-52.[17] KLINKENBERG C,RAABE D,LUCKE K. Influence of intercritical annealing on the texture formation in low-carbon steel strips[J]. Steel Research,1993,64(5):262-266.[18] DANIEL D,SAVOIE J,JONAS J J. Texture induced by tension and deep drawing in low carbon and extra low carbon steel sheets[J]. Acta Metallurgica et Materialia,1993,41(6):1905-1920.[19] HUTCHINSON W B,REDE L,LINDH E,et al. Texture in hot rolled austenite and resulting transformation products[J]. Materials Science and Engineering:A,1998,257(1):9-17.[20] EMADODDIN E,AKBARZADEH A,DANESHI G. Effect of cold rolling reduction and intercritical annealing temperature on the bulk texture of two TRIP-aid steel sheets[J]. Journal of Materials Process Technology,2008,203(1-3):293-300.