共查询到19条相似文献,搜索用时 78 毫秒
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在实验室加工了具有不同稀土、钛和铌含量的冷轧搪瓷钢板,测定了钢板的再结晶温度和模拟退火后钢板的成形性能,并观察了其金相组织,分析了钢中的第二相粒子。结果表明,在单加稀土、复合添加稀土 钛或稀土 钛 铌的3种钢中,单加稀土的钢再结晶温度最低,而含稀土 钛 铌的钢再结晶温度最高;经高温退火后,含稀土 钛 铌钢的伸长率和r值在3者中最高,达到了超深冲(即EDDQ)级别。 相似文献
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采用Gleeble3500热模拟试验机,研究了含铌Q345钢奥氏体静态再结晶行为、铌的碳氮化物在奥氏体和铁素体中的析出行为等实验,铌在钢中的强化作用机理。根据上述结论,邯钢2250热轧厂生产了以碳、锰为主要成分,并加入微量铌元素,将原热轧带钢Q345的屈服强度由345 MPa提高到550M Pa。对生产的微铌处理550 M Pa钢的组织和力学性能作了检验,在细晶强化、沉淀强化和相变强化等复合强化的综合作用下,热轧带钢屈服强度均达到550 MPa以上,塑性良好。 相似文献
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为了研究和设计高强钢筋添加铌、钒后轧制过程中对奥氏体区再结晶行为的量化管控,采用Gleeble-3500热模拟机对铌、钒微合金化高强螺纹钢进行单轴热压缩试验,基于再结晶临界条件的热力学原理,通过对不同形变条件下应力-应变曲线分析,采用Avrami方程得到了不同变形条件下的再结晶动力学曲线,并根据再结晶动力学曲线,量化对比分析了铌、钒微合金化对高强螺纹钢再结晶开始、转变及终了过程的影响。结果表明,铌、钒微合金化螺纹钢的热压缩过程均呈现了明显的动态再结晶特征,由于微合金元素Nb/Nb+V的添加,阻碍了20MnSi钢的动态再结晶,变形温度的提高或应变速率的增加可促进再结晶。针对生产中利用动态再结晶而组织调控进行了工艺设计,精轧机组中成品机架前进行冷却和回复,确保830 ℃左右有利再结晶分数达到95%。 相似文献
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通过对硬度异常钢板的生产工艺进行分析发现,钢板中铌含量过高是造成同一生产工艺下钢板硬度异常的主要原因。利用冷轧退火模拟试验装置,模拟了3种不同铌含量低碳钢板在不同温度条件下的退火过程,通过对比分析样板显微组织和力学性能,研究微量铌对低碳钢退火再结晶组织和性能的影响。结果表明,当钢中含有微量铌元素时,低碳钢的再结晶完成温度显著提升。含铌0.0012%和0.0023%的低碳钢要满足T5料的性能要求,退火温度应提高至650℃。 相似文献
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通过热连轧带钢温度场的有限元分析以及带钢热连轧过程的再结晶动力学和应变累积的研究,建立了精轧过程平均流变应力模型:静态再结晶平均流变应力σk=k1 exp{0.126-1.75[C] 0.594[C]^2 (2851 2968[C]-1120[C]^2)/T/ε^0.21ε^0.13,其中T-再结晶温度/K,ε-应变,ε-应变速率/s^-1,k1-系数;动态再结晶平均流变应力σD=9.8σB(1-Xdyn) 1.14σBB Xdyn,其中Xdyn-动态再结晶率,σBB-动态再结晶进入稳态时应力。X46级管线钢(%:0.07C-0.97Mn-0.33Si-0.018Nb)工业轧制时轧制压力的实测数据与该模型预测数据吻合良好。 相似文献
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超低碳高强度烘烤硬化钢织构与性能 总被引:1,自引:1,他引:0
研制了含铌加磷超低碳高强度烘烤硬化钢,它具有优良的力学性能和基本成形性,高的烘烤硬化值。采用ODF织构分析技术研究了冷轧变形织构和退火过程(回复,再结晶和晶粒长大)再结晶织构的演变。讨论了再结晶织构γ-〈111〉//N,D形成机理。 相似文献
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The dynamic recrystallization behavior of hot rolled TRIP steel produced by CSP process was studied by means of Gleeble-3500 thermal simulation testing machine in the temperature range of 950-1150℃ with the strain rate of 0.1-10s-1 and the strain of 65%. And the effect of initial austenite grain size on the dynamic recrystallization behavior of TRIP steel was explored. The results show that the finer initial austenite grain size, the higher deformation temperature and the lower strain rate, the more positive austenite dynamic recrystallization of TRIP steel. Moreover, it is found that when the coarse grained samples (initial austenite grain size is 767.54μm) deform in the range of 1050℃ to 1150℃, the austenite dynamic recrystallization will take place, and the dynamic recrystallization activation energy of TRIP steel is deduced as 361539.17J/mol. The Zener-Hollomon parameter equation as a function of strain rate and temperature is determined. And the model of critical strain for dynamic recrystallization, the flow stress model of austenite at high temperature and the grain size model for dynamic recrystallization are also established. The calculation results are coincided well with the experimental results. 相似文献
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M. R. Barnett G. L. Kelly P. D. Hodgson 《Metallurgical and Materials Transactions A》2002,33(7):1893-1900
A general relationship between the kinetics of dynamic and static recrystallization is developed. It is predicted that conventional
dynamic recrystallization will occur whenever the deformation time exceeds the adjusted start time for static recrystallization.
This approach is verified using data for austenite and lead. It is then applied to current and previous work on ferrite. The
model provides support for the contention that conventional dynamic recrystallization occurs in low carbon ferrite if deformation
is carried out at high temperatures and low strain rates. In the present work, which was carried out at 700 °C, evidence for
dynamic recrystallization was observed for strain rates less than around 0.01 s−1. At higher strain rates, the model predicts a critical strain for the onset of dynamic recrystallization that exceeds the
critical strain for the beginning of the recovery steady-state region. While the model allows dynamic recrystallization to
begin in this region, the critical strain for its onset is expected to increase rapidly with increasing strain rate and decreasing
temperature once steady state has been reached. 相似文献
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摘要:采用Gleeble-3500热模拟试验机,在温度为950~1150℃、应变速率为0.1~10s-1和变形量为65%的条件下研究了CSP热轧TRIP钢的动态再结晶行为,探讨了初始奥氏体晶粒尺寸对TRIP钢动态再结晶行为的影响。研究结果表明,初始奥氏体晶粒尺寸越小,变形温度越高,应变速率越慢时,TRIP钢中奥氏体越易发生动态再结晶。其中,粗晶试样(初始奥氏体晶粒尺寸为767.54μm)在1050~1150℃内变形时,将发生动态再结晶。其热变形激活能为361539.17J/mol,确定了Zener-Holloman参数与应变速率和温度的关系式,建立了动态再结晶临界应变模型、高温奥氏体流动应力模型和动态再结晶晶粒尺寸模型,理论模拟结果与试验结果吻合较好。 相似文献
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Numerical Simulation of Austenite Recrystallization in CSP Hot Rolled C-Mn Steel Strip 总被引:2,自引:0,他引:2
TANG Guang-bo LIU Zheng-dong DONG Han GAN Yong KANG Yong-lin LI Lie-jun MAO Xin-ping 《钢铁研究学报(英文版)》2007,14(4):49-55,60
An integrated mathematical model is developed to predict the microstructure evolution of C-Mn steel during multipass hot rolling on the CSP production line,and the thermal evolution,the temperature distribution,the deformation,and the austenite recrystallization are simulated.The characteristics of austenite recrystallization of hot rolled C-Mn steel in the CSP process are also discussed.The simulation of the microstructure evolution of C-Mn steel ZJ510L during CSP multipass hot rolling indicates that dynamic recrystallization and metadynamic recrystallization may easily occur in the first few passes,where nonuniform recrystallization and inhomogeneous grain size microstructure may readily occur;during the last few passes,static recrystallization may occur dominantly,and the microstructure will become more homogeneous and partial recrystallization may occur at relatively low temperature. 相似文献
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含Sc铝镁合金的超塑变形机制 总被引:1,自引:0,他引:1
采用透射电镜研究了含微量Sc元素的AlMg合金在超塑变形过程中的显微组织和位错行为。结果表明:合金在超塑变形过程中发生了四个连续过程:①动态再结晶;②晶界向晶内激发位错;③位错在晶内密集并且受到第二相Al3Sc质点的阻碍作用,同时通过攀移越过晶内弥散分布的Al3Sc粒子;④位错向晶界运动并在晶界处消失。动态再结晶是合金在超塑变形中存在的组织效应,起到了细化晶粒,诱发微细晶超塑性的作用。该合金超塑变形的主要机制为晶界滑动伴随晶内位错运动 相似文献
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�����䣬����ΰ������������������������ 《钢铁研究学报》2014,26(10):55-59
The effect of deformation parameters on hot deformation of superalloy 800H was studied by means of single-pass compression test. It was found that smaller initial grain size, higher deformation temperature and lower strain rate are more easily to cause dynamic recrystallization. And when dynamic recrystallization can take place during deformation, the fraction of dynamic recrystallization increases with increasing of strain. The models of dynamic recrystallization activation energy, critical strain, dynamic recrystallization kinetics, dynamic recrystallization kinematics and grain size of dynamic recrystallization for 800H were obtained through the analysis of data obtained by single-pass compression. The variation tendency for grain size simulated by Deform-2D is consistent with metallographic statistics, and the average error is 4. 5??m. Very small average error shows that the model is consistent with practical situation and can be used to predict recrystallized grain size for 800H during thermal deformation. 相似文献
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??The hot compression tests of 2. 25Cr1Mo steel at 950-1200??, 0. 01-10s-1, and deformation of 60% were carried out on a Gleeble- 1500D simulator. The effects of deformation temperature and strain rate on the dynamic recrystallization of 2. 25Cr1Mo steel were investigated. The models for dynamic recrystallization critical strains and dynamic recrystallization fraction were established. The results show that 2. 25Cr1Mo steel is more likely to undergo dynamic recrystallization at high temperature and high strain rate. The deformation activation energy and critical strains in dynamic recrystallization as well as dynamic recrystallization fraction model of 2. 25Cr1Mo steel were obtained. The constitutive equation of 2. 25Cr1Mo steel was constructed and the dynamic recrystallization physical metallurgical model of finite element software data interface was established. The model provides the basic conditions for the forging microscopic simulation of large forgings. 相似文献