相较于传统冷轧TRIP钢生产方式,采用热轧板结合动态配分方式更加符合TRIP钢工业生产需求。采用C-Si-Mn钢热轧板结合炉冷方式制备高强高塑的相变诱导塑性（TRIP）钢,并利用SEM、EBSD、TEM、热模拟试验机、拉伸试验机等设备系统研究淬火结束温度对炉冷TRIP钢贝氏体相变、残余奥氏体稳定性及力学性能的影响规律。结果表明,当淬火结束温度低于或接近Ms（马氏体转变开始温度,200 ℃和250 ℃）,淬火和炉冷阶段主要发生马氏体相变,贝氏体相变很难发生。当淬火结束温度达到300 ℃时,开始形成板条状贝氏体,随着淬火结束温度升高,贝氏体含量增加,且贝氏体形态由板条状向粒状转变。残余奥氏体体积分数及尺寸随淬火结束温度升高而增加,残余奥氏体碳含量开始基本保持不变,但当淬火结束温度超过400 ℃时出现明显下降。TRIP钢的抗拉强度随淬火结束温度呈先降低后升高的趋势,而伸长率和强塑积则先升高后降低。当淬火结束温度为350 ℃时,TRIP钢获得最佳塑性（伸长率）和强塑积,分别为32.73%和33.06 GPa·%,其获得最佳塑性主要归因于较高含量的残余奥氏体以及残余奥氏体合适的机械稳定性,这能显著扩展TRIP效应区间。以上结果说明,采用炉冷过程的动态配分方式能实现贝氏体相变和碳配分,通过控制炉冷前的淬火结束温度能获得不同体积分数及稳定性的残余奥氏体,从而提高TRIP钢的强塑性。残余奥氏体体积分数并不是影响TRIP效应及TRIP钢塑性的决定性因素,奥氏体机械稳定性对塑性同样有重要影响。
Abstract
Compared with the traditional cold-rolled TRIP steel production method, the use of hot-rolled plate combined with dynamic partitioning method is more in line with the industrial production needs of TRIP steel. Therefore, C-Si-Mn steel hot-rolled plate combined with furnace cooling method was used to prepare high-strength and high plasticity phase transiformation induced plasticity （TRIP） steel,and the effect of final quenching finish temperatures on bainitic transformation,the stability of retained austenite and mechanical properties of furnace cooled TRIP steel was systematically studied. The microstructure and mechanical properties were analyzed by means of SEM,EBSD,TEM,thermal simulation test machine and tensile testing machine. The results indicate that when the final quenching temperature is lower than or close to Ms temperature （200 ℃ and 250 ℃）,the transformation of martensite mainly occures and bainitic formation is inhibited during the quenching and furnace cooling. When the quenching finish temperature reaches 300 ℃,lathy bainite begins to form. With the increase of quenching finish temperature,the content of bainite increases,besides,the morphology of bainite changes from lathy to granular. The content and size of retained austenite increases with the quenching finish temperature,and the C content of retained austenite is remained basically unchanged firstly,and then decreases significantly when the quenching finish temperature exceeds 400 ℃. The tensile strength of TRIP steel decreases first and then increases with final quenching temperature increase,while the elongation and product of strength and elongation （PSE） increases first and then decreases. When the quenching finish temperature is 350 ℃,the optimum plasticity and PSE are obtained,which is 32.73% and 33.06 GPa·%,respectively. The optimal plasticity is mainly attributed to the high content of retained austenite and the appropriate mechanical stability of retained austenite,which can significantly extend the range of TRIP effect. The above results show that the dynamic partitioning method of furnace cooling process can achieve C partitioning and bainitic transformation. The volume fraction of retained austenite and mechanical stability can be controlled by adjusting the final quenching temperature before furnace cooling,so as to improve the mechanical properties of TRIP steel. The volume fraction of retained austenite is not the determining factor affecting the TRIP effect and the plasticity of TRIP steels. The mechanical stability of retained austenite also playes a significant role.
关键词
C-Si-Mn热轧板 /
淬火结束温度 /
动态配分 /
TRIP钢 /
奥氏体稳定性 /
力学性能 /
强塑积
{{custom_keyword}} /
Key words
C-Si-Mn hot-rolled sheet /
quenching finish temperature /
dynamic partitioning /
TRIP steel /
stability of retained austenite /
mechanical property /
product of strength and elogation
{{custom_keyword}} /
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 李麟. 汽车用高强钢的发展与展望[J]. 上海金属,2022,44(3):1.(LI L. Development and prospect of high strength steel for automobile[J]. Shanghai Metals,2022,44(3):1)
[2] 董瀚,王毛球,翁宇庆. 高性能钢的M3组织调控理论与技术[J]. 钢铁,2010,45(7):1.(DONG H,WANG M Q,WENG Y Q. Performance improvement of steels through M3 structure control[J]. Iron and Steel,2010,45(7):1)
[3] WANG H S,YUAN G,ZHANG Y X,et al.Microstructural evolution and mechanical properties of duplex TRIP steel produced by strip casting[J]. Materials Science and Engineering A,2017,692:43.
[4] SOHRABI M J,MIRZADEH H,SADEGHPOUR S,et al.Grain size dependent mechanical behavior and TRIP effect in a metastable austenitic stainless steel[J]. International Journal of Plasticity,2023,160:103502.
[5] XU X,XU B Y,CHEN P,et al.Effect of austenite stability on the hole expansion behavior of δ-TRIP steels[J]. Materials Today Communications,2020,24:101034.
[6] SKOWRONEK A,GRAJCAR A.Effect of deformation temperature on the mechanical behavior and stability of retained austenite in TRIP-assisted medium-C multiphase steel[J]. Materials,2020,13(11):2433.
[7] SHEN Y F,LIU Y D,SUN X,et al.Improved ductility of a transformation-induced-plasticity steel by nanoscale austenite lamellae[J]. Materials Science and Engineering A,2013,583:1.
[8] SONG F,LIU Q N,MENG S H,et al.A universal Biot number determining the susceptibility of ceramics to quenching[J]. Europhysics Letters,2009,87:54001.
[9] RYU J H,KIM D I,KIM H S,et al.Strain partitioning and mechanical stability of retained austenite[J]. Scripta Materialia,2010,63(3):297.
[10] XIE Z J,REN Y Q,ZHOU W H,et al.Stability of retained austenite in multi-phase microstructure during austempering and its effect on the ductility of a low carbon steel[J]. Materials Science and Engineering A,2014,603:69.
[11] 田亚强,田耕,郑小平,等. 淬火配分贝氏体钢不同位置残余奥氏体C、Mn元素表征及其稳定性[J]. 金属学报,2019,55(3):332.(TIAN Y Q,TIAN G,ZHENG X P,et al. C and Mn elements characterization and stability of retained austenite in different locations of quenching and partitioning bainite steels[J]. Acta Metallurgica Sinica,2019,55(3):332)
[12] GRAJCAR A,KRZTOŃ H.Effect of isothermal bainitic transformation temperature on retained austenite fraction in C-Mn-Si-Al-Nb-Ti TRIP-type steel[J]. Journal of Achievements in Materials and Manufacturing Engineering,2009,35(2):169.
[13] 江海涛,唐荻,刘强,等. TRIP钢中残余奥氏体及其稳定性的研究[J]. 上海金属,2007,29(5):155.(JIANG H T,TANG D,LIU Q,et al. Investigation of retained austenite and its stabilization in trip steel[J]. Shanghai Metals,2007,29(5):155)
[14] 陈光辉,徐光,胡海江,等. 1.6 GPa级中碳高强贝氏体钢残余奥氏体调控机理[J]. 钢铁,2021,56(2):110.(CHEN G H,XU G,HU H J,et al. Controlling mechanism of retained austenite in a 1.6 GPa grade medium-carbon high-strength bainitic steel[J]. Iron and Steel,2021,56(2):110)
[15] ZHANG Y,HUO W F,SONG R B,et al.The effect of isothermal bainitic transformation time on austenite stability of TRIP-980 steel with high ductility[J]. Materials Letters,2022,326:132927.
[16] XU X,LIU R D,XU B Y,et al.Effects of bainite isothermal temperature on microstructure and mechanical properties of a δ-TRIP steel[J]. IOP Conference Series:Materials Science and Engineering,2020,739:012022.
[17] KANG J,LI Y J,WANG X H,et al.Design of a low density Fe-Mn-Al-C steel with high strength-high ductility combination involving TRIP effect and dynamic carbon partitioning[J]. Materials Science and Engineering A,2019,742:464.
[18] ZHANG B,DU L X,DONG Y.Structure-property relationship in novel low carbon hot-rolled TRIP steels via thermo-mechanical controlled processing and coiling[J]. Materials Science and Engineering A,2020,771: 138643.
[19] SU Y Y,CHIU L H,CHUANG T L,et al.Retained austenite amount determination comparison in JIS SKD11 steel using quantitative metallography and X-ray diffraction methods[J]. Advanced Materials Research,2012(482/483/484):1165.
[20] SANTOFIMIA M J,ZHAO L,PETROV R,et al.Microstructural development during the quenching and partitioning process in a newly designed low-carbon steel[J]. Acta Materialia,2011,59(15):6059.
[21] HAJYAKBARY F,SIETSMA J,MIYAMOTO G,et al.Analysis of the mechanical behavior of a 0.3C-1.6Si-3.5Mn(wt%) quenching and partitioning steel[J]. Materials Science and Engineering A,2016,677:505.
[22] FRANCESCHI M,PEZZATO L,GENNARI C,et al.Effect of intercritical annealing and austempering on the microstructure and mechanical properties of a high silicon manganese steel[J]. Metals,2020,10(11):1448.
[23] PARK H S,HAN J C,LIM N S,et al.Nano-scale observation on the transformation behavior and mechanical stability of individual retained austenite in CMnSiAl TRIP steels[J]. Materials Science and Engineering A,2015,627:262.
[24] 赵佳莉,张福成,于宝东,等. 70Si3MnCrMo钢中贝氏体及其回火稳定性[J]. 钢铁,2017,52(1):71.(ZHAO J L,ZHANG F C,YU B D,et al. Bainite microstructure and its tempering stability of 70Si3MnCrMo steel[J]. Iron and Steel,2017,52(1):71)
[25] BHADESHIA H K D H. Bainite in steels:Theory and practice[M]. 3rd ed. London:CRC Press,2015.
[26] 于庆波,段贵生,孙莹,等. 粒状贝氏体组织对低碳钢力学性能的影响[J]. 钢铁,2008,43(7):68.(YU Q B,DUAN G S,SUN Y,et al. Effect of granular bainite on mechanical properties of low-carbon steel[J]. Iron and Steel,2008,43(7):68)
[27] DAN W J,LI S H,ZHANG W G,et al.The effect of strain-induced martensitic transformation on mechanical properties of TRIP steel[J]. Materials and Design,2008,29(3):604.
[28] SOLEIMANI M,KALHOR A,MIRZADEH H.Transformation-induced plasticity(TRIP)in advanced steels:A review[J]. Materials Science and Engineering A,2020,795:140023.
[29] OLSON G B,AZRIN M.Transformation behavior of TRIP steels[J]. Metallurgical Transactions A,1978,9(5):713.
[30] ZHOU Q,QIAN L H,TAN J,et al.Inconsistent effects of mechanical stability of retained austenite on ductility and toughness of transformation-induced plasticity steels[J]. Materials Science and Engineering A,2013,578:370.
[31] 程远遥,赵刚,许德明,等. 奥氏体化温度对Si-Mn钢热轧板淬火-配分处理后显微组织和力学性能的影响[J]. 金属学报,2023,59(3):413.(CHENG Y Y,ZHAO G,XU D M,et al. Effect of austenitizing temperature on microstructures and mechanical properties of Si-Mn hot-rolled plate after quenching and partitioning treatment[J]. Acta Metallurgica Sinica,2023,59(3):413.)
[32] LEE S,LEE S J,DE COOMAN B C. Austenite stability of ultrafine-grained transformation-induced plasticity steel with Mn partitioning[J]. Scripta Materialia,2011,65(3):225.
[33] HILDITCH T,BELADI H,HODGSON P,et al.Role of microstructure in the low cycle fatigue of multi-phase steels[J]. Materials Science and Engineering A,2012,534:288.
[34] LI Y J,LIU D,CHEN D,et al.Response of retained austenite to quenching temperature in a novel low density Fe-Mn-Al-C steel processed by hot rolling-air cooling followed by non-isothermal partitioning[J]. Materials Science and Engineering A,2019,753:197.
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}
基金
国家自然科学基金青年基金资助项目（52304411）;国家自然科学基金联合基金资助项目（U22A20173）;湖北省自然科学基金资助项目（2023AFA062）
{{custom_fund}}
