共查询到20条相似文献,搜索用时 159 毫秒
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1.概述采用辊温高达460℃~530℃的热辊进行迭轧薄板的轧机,为了防止迭板产生粘结,其轧制温度控制在奥氏体加铁素体显微组织区域内,一般在760~880℃。即开轧温度仅相当于热轧型钢的终轧温度,它的终轧温度又低于钢的再结晶温度。其变形特点介乎热 相似文献
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研究了15MnMoVTi钢变形的奥氏体再结晶的特征。给出了奥氏体再结晶的临界变形量和再结晶的三个温度区间:温度高于1050℃为动态再结晶区,900~1050℃为静态再结晶区,低于900℃为未再结晶区。再结晶延迟时间达20秒。 15MnMoVTi钢的加热温度在1050~1200℃范围为宜,最佳温度在1150℃左右。轧制总变形量应大于50%,同时应严格控制终轧温度并采用快速冷却措施。影响轧后奥氏体晶粒度的主要因素是终轧温度和轧后冷却速度。 相似文献
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以钛微合金化的355 MPa级低合金高强度钢为研究对象,将试验钢分别在830、800、750、700 ℃系列温度下终轧,研究了终轧温度对显微组织和力学性能的影响。结果表明,随着终轧温度的降低,屈服强度和抗拉强度呈现不断升高的趋势,伸长率和冲击性能呈现先升高后下降的趋势,在Ar3温度附近终轧,钢板可获得最佳的综合力学性能。不同终轧温度下钢板基体组织均为铁素体+珠光体,在800 ℃终轧钢板晶粒最为均匀细小,830 ℃终轧钢板晶粒较800 ℃终轧相对粗大,750 ℃终轧钢板组织出现混晶现象,700 ℃终轧时,钢板晶粒已经拉长变形,一定程度上出现“纤维状铁素体”。充分细化晶粒可以减轻钢板中的带状组织。 相似文献
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通过加压冶炼、控制轧制方式获得氮质量分数为0.59%的Mn18Cr18N钢板,研究了终轧温度对高氮奥氏体钢组织和力学性能的影响。结果表明,在再结晶区轧制并且终轧温度为970 ℃的钢板,组织为奥氏体等轴晶和部分孪晶,强度较低,塑性、冲击韧性较好;终轧温度为910 ℃的钢板,大部分组织为变形奥氏体晶粒,有少量再结晶晶粒,随着终轧温度降低钢板强度升高,塑性和冲击韧性降低;在未再结晶区轧制并且终轧温度为780 ℃的钢板,组织为变形严重的奥氏体晶粒,强度最高,塑性、韧性最低。所有试验钢有晶界析出的Cr2N相,降低终轧温度和减缓轧后冷却速度,会增加Cr2N相的析出。 相似文献
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为开发强度级别为685MPa的高强钢板的控轧控冷工艺,研究了终轧温度,未再结晶区累积压下量,终冷温度,冷却速度等工艺参数对钢的显微组织和力学性能的影响。实验结果表明,在控轧控冷条件下,钢的室温显微组织由铁素体和贝氏体组成,贝氏体主要以粒状贝氏体为主,此外,晶粒细化是提高钢的强度和韧性的最有效的手段。 相似文献
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�����࣬�λ�ƽ�������������𣬴����� 《钢铁研究学报》2013,25(8):46-50
By using the thermal simulation technology, the effect of RE on the recrystallization behavior of low-carbon micro-alloyed steel was investigated in the laboratory. The results show that, effect of RE composition on dynamic recrystallization critical strain ??D is more obvious, the critical strain of RE content to 100??10-6 and RE content to 60??10-6 samples are higher than the without RE samples, and with the amount of RE increase, the recrystallization is no longer to occur when the deformation temperature reached 910??, so dynamic recrystallization is delayed to occur by adding of RE, and the delayed effect was more obvious with the addition of rare earth increased. Effect of RE on double-pass static recrystallization softening rate at high-temperature is more obvious than that of low temperature rolling. And compared without RE samples, additting the appropriate amount of RE deformation resistance is improved obviously. So recrystallization easily occurs in the pass-interval times, while less rare earth content has no significant effect. 相似文献
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Joseph D. Robson 《Metallurgical and Materials Transactions A》2014,45(8):3205-3212
Magnesium alloys that contain certain rare-earth (RE) additions are known to have improved formability and this can be partly attributed to the different texture they display after recrystallization. Previous experimental work has identified segregation of RE to grain boundaries and dislocations as being potentially important in producing this change in behavior. In the present paper, two classical models (Langmuir–McClean and Cahn–Lücke–Stüwe) are used to explore the likely effect of RE additions on grain boundary solute concentration and drag. It is demonstrated that a wide range of RE elements are predicted to segregate strongly to grain boundaries due to the large atomic size misfit with magnesium. The maximum level of segregation is produced for elements such as Y or Gd that combine a high misfit and high bulk solubility. Segregated Y is predicted to produce a solute drag pressure on migrating boundaries several orders of magnitude greater than that obtained by Al or Zn additions. It is demonstrated that while this drag is predicted to be insufficient to strongly retard static recrystallization under typical annealing conditions, it is expected to suppress dynamic recrystallization by any mechanism requiring boundary migration. 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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According to EET theory, the valence electron structures of RE in the solid solution of austenite, pearlite and martensite were calculated. The influence of RE in solid solution on phase transformation of pearlite and recrystallization of martensite was explained by the valence electron structure data of phases. Calculating results indicate that C element is favorite to enhance the number of RE in the solid solution. RE in the solute solution shortens the incubation period of proeutectoid ferrite, increases its quantity and carbon content, decreases the quantity of pearlite and thickness of its lamellas and lamellar spacing, then the strength and hardness of pearlite are improved and granular pearlite can be obtained. RE dissolved in martensite intensifies martensite, enhances tempering stability of martensite, increases its recrystallization temperature and prolongs the holding time needed during tempering. 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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BH08G焊接用钢的热变形行为及动力学再结晶模型 总被引:1,自引:1,他引:0
用Gleeble-1500热模拟试验机研究了成分(% )为。.08C、l. 59Mn、0.34Mo、0.12Ti的BH08G焊接用 钢在950 ~ 1050℃ 、变形速率 ε 为0.1 ~ 10.0 s -1时的热变形行为。通过奥氏体再结晶动力学回归计算得出: BH08G钢的Zener-Hollomon参数Z与峰值应力的关系式为Z =3. 829 x 1012exp(0.046 46 δm); 峰值应力 δm、动态再结晶临界应变εc、峰值应变εm、动态再结晶完成应变εs与InZ的关系为:δm=21.338InZ-516.49,εc≈ 0.83εm= 0.032 6InZ-0.732, εs=0.052 2InZ -0.980 1 。通过BH08G钢动态再结晶状态图得出,BH08G钢粗轧温度为980 ~ 1 050 ℃、精轧温度为930 -980℃有利于变形晶粒细化,改善材料的力学性能。 相似文献
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Effects of RE and Vanadium on Microalloyed Steel 总被引:2,自引:0,他引:2
The effects of RE were studied by TEM, SEM, ICP and thermal simulation methods in vanadium microalloyed steel. The content.of RE in the solid solution can reach the order of 10^-5 --10^-4 in steel. The solid solution of RE was found to reduce the stability of precipitated V (C, N ), impede the precipitation of V (C, N ) in austenite, and accelerate and refine the precipitation of V (C, N) in ferrite. The combined effect of RE and V is to delay the dynamic recrystaUization, refine the grains and second phase particles, and to promote the precipitation of V (C, N) obviously. Thus the microalloying with RE and V leads to raising the strength and toughness of steel. 相似文献