X70管线钢热连轧过程奥氏体再结晶、晶粒尺寸 和平均流变应力的预测

在考虑动态、亚动态再结晶及静态再结晶的基础上,建立了X70管线钢的物理冶金模型,并应用于板带钢热连轧过程奥氏体再结晶、晶粒尺寸和流变应力的预测.结果表明,在合理的温度和压下条件下,应变累积可导致在精轧过程出现动态 亚动态再结晶行为,促进奥氏体晶粒的进一步细化.终轧温度的降低可引起奥氏体晶粒的粗化和残余应变的显著提高.建立了考虑晶粒尺寸和残余应变影响的平均流变应力(MFS)的人工神经网络预测模型,大大提高了热连轧过程MFS预测精度.     

X80热连轧管线钢的成分、工艺对组织及性能的影响

对三种不同成分设计的Mn-Mo-Nb+钢的精轧轧程、轧制温度以及C、Mo含量对热轧板卷屈服强度和DWTT撕裂面积等性能的影响进行了研究,所得到的结论对提高强度,细化奥氏体晶粒,避免混晶具有指导性。采用含Mo低碳、高Nb设计,控制精轧轧程,可以获得具有优良强度和韧性的X80热连轧管线钢产品。     

400 MPa超级钢热连轧过程中再结晶及流变应力的预测

开发了描述低碳钢软化行为的再结晶模型,并对奥氏体再结晶动力学和微观组织演变进行了模拟计算。在此基础上建立了计算机精轧过程应力-应变模型,根据现场数据预测了400MPa级超级钢细晶化轧制的轧制力,预测结果与实验值吻合,这项研究可广泛用于钢种开发,轧制规程设定和优化以及轧制过程的在线控制。     

Slow Hot Rolling in Direct Linkage with Thin Slab and Strip Continuous Casting: Effect on the Evolution of Austenite Grain

This work was carried out in context with the development of strip casting with the single‐belt process. In this new process the hot rolling is performed in‐line with considerably lower velocity than in conventional hot rolling. It is of interest to study the effect of low rolling speed on the material properties. Based on a finite element model used to predict the thermomechanical behaviour of the strip in tandem mills, the microstructural evolution of austenite was computed. In order to take account of the non‐isothermal conditions in industrial hot rolling, the material equations for recrystallization and grain growth are modified. The parameter studies were carried out over a wide range of volumetric flow rate extending from that in thin slab casting to that in conventional finishing rolling. They demonstrate that the “slow hot rolling” can produce a fine grain of austenite. Austenite grain evolution was computed for conventional rolling with a seven stand mill and for in‐line hot rolling of strip produced by the single‐belt process. It is found that the final grain size of austenite is about the same for the two processes under the condition that strip thickness behind the last stand is the same.     

X46级管线钢热连轧过程中温度场及平均流变应力的预测

采用有限元计算模型和实测轧件温度以及精轧各道次的轧制压力值，对不同边界条件下的传热系数和塑性功转热率进行了优化计算，得到了轧件断面温度场。在此基础上考虑了再结晶等因素，建立了计算精轧过程中应力一应变曲线的流变应力模型，并利用该模型对X46级管线钢精轧各道次的流变应力进行了预测。结果表明：该模型的计算结果与用Sims法计算的结果吻合较好，能真实反映工业生产的实际情况。     

C-Mn钢窄带热轧时的再结晶软化规律

针对唐山钢铁有限责任公司带钢厂的生产实际,借助理论与实验结果,研究了C-Mn钢热轧过程中各道次奥氏体的再结晶规律,计算结果与实测结果吻合较好,说明给出的组合模型用于窄带热轧的生产是可行的,它为在生产中控制与预报带钢的组织性能提供了奥氏体再结晶的定量化基础,并为再结晶软化不充分时的力能计算提供了修正依据.     

热轧带钢层流冷却系统的设计

本钢１７００ｍｍ热轧带钢层流冷却系统采用的是带钢管层流冷却和高压喷嘴冷却相结合的方式。介绍了此系统的设计过程及总用水量和上喷、下喷和侧喷水量的计算。     

Precise calculation of average strain and average strain rate considering roll elastic flattening

Considering roll elastic flattening,newequations were proposed to calculate the average strain ε and·average strain rate ε in the hot strip rolling process. By comparing the proposed equations with currently used equations,it was observed that the strain rate of thick strip and strain are not sensitive to roll elastic flattening.However,for thin strip,a noticeable calculated difference in the strain rate occurred when roll elastic flattening was considered.     

低碳钢热连轧过程中工艺参数及组织演变的预测

采用二维有限元法对热连轧生产过程中沿带钢厚度方向的温度场分布进行了预测,建立了描述低碳钢软化行为的再结晶模型,并利用此模型对奥氏体再结晶动力学及微观组织演变进行了模拟计算,建立了计算精轧过程应力-应变曲线的流变应力模型,根据现场数据,对400MPa级超级钢细晶工业轧制实验的轧制力、轧制力矩和轧制功率进行了预测,结果与实测值吻合较好,反映了工业生产实际。     

TSCR生产X65管线钢过程的再结晶研究和MFS预测

在有限元差分法模拟温度场基础上,预测了管线钢TSCR过程的组织演变及断面分布规律,建立了考虑晶粒尺寸和再结晶影响的平均流变应力模型,提出了细晶轧制的工艺窗口.随着温度降低,精轧后几道次几乎没有再结晶发生;加大精轧区前两个道次压下量或者降低精轧入口温度可实现奥氏体晶粒细化;模型预测值与工业实测数据吻合良好.     

Non-Oriented Fe-Si Thin Strip Produced from Grain Oriented Fe-Si Strip by CSR

The grain oriented silicon strip was rolled by cross shear rolling (CSR) and then an-nealed to manufacture non-oriented thin silicon strip of high quality. The recrystallization ofrolled grain-oriented silicon steel into non-oriented silicon steel was studied. For this purpose,CSR is better than conventional rolling, and the higher the mismatched speed rate is, the betterthe properties of the non-oriented thin silicon strip are. The optimum annealing schedule isheating at 1 000 :C for 1 h in pure hydrogen atmosphere added with H2S of O. 001 0 %.     

日本热轧带钢无头轧制工艺与设备的开发

重点介绍了日本川崎钢铁公司千叶厂无头轧制工艺及设备概况,对鞍钢１７８０热带钢机组今后采用无头轧制技术有一定参考价值。     

热轧润滑应用效果的因素分析

介绍了板带热轧润滑的机理，分析了影响热轧润滑使用效果的因素，同时提出进一步改善热轧润滑效果应重视的问题。     

基于Z参数金属热变形分段流变应力模型研究

考虑峰值应力后的稳态应力的软化机制,构建了包括动态回复和动态再结晶过程的基于Z参数的金属热成形分段流变应力数学模型,在Gleeble-3500热力模拟试验机上采用圆柱试样对金属材料进行了进行恒温和恒速热压缩变形试验,研究其在高温塑性变形过程中流变应力的变化规律,确定其形变表观激活能Q和应变硬化指数n,得到了峰值应力,峰值应变,稳态应力与lnZ的线性关系以及动态回复参数和动态再结晶动力学的数学模型,分段流变应力模型的模拟结果与试验结果吻合较好.     

高碳钢高速变形的模拟及再结晶规律的研究

高碳钢试样在Ｇｌｅｅｂｌｅ－２０００试验机上进行高温多道次高变形速度的变形试验,高应变速率下的变形屈服应力服从Ｚｅｎｅｒ－Ｈｏｌｌｍａｎ因子（Ｚ＝Ａｏ＾ｎ＝εｅｘｐ（Ｑ／ＲＴ）的变化。高线预精轧时,发生道次间静态再结晶;而精轧时由于道次时间短,有道次应变积累现象,应变积累达到临界变形量后,引起动态再结晶发生。     

含铌微合金带钢精轧过程中的再结晶行为

介绍了含铌微合金带钢在精轧过程中的再结晶行为。在不同条件下,含铌钢将发生静态再结晶、动态再结晶和亚动态再结晶,而且沉淀的析出对再结晶有不同程度的影响。