精轧负荷分配自动实现技术及应用

运用KDD技术对热轧带钢生产中过程机大量历史数据和积累了多年的轧制信息(包括轧制负荷相关的信息)进行预处理和数据挖掘,并结合相应的理论知识,开发了适合现场生产的负荷分配模型.该模型能实施多种功能,并在实践中取得成功应用,实现了负荷分配的自动设定,形成了规范的负荷分配制度.同时给出了负荷分配模型的优化方法.     

2160mm热轧精轧温度控制模型

本文简介了２１６０ｍｍ热轧精轧温度控制模型的操作原理及控制，阐述了利用该模型计算和调节轧制中间坯的轧制条件。     

攀钢热轧板厂二期改造后精轧工艺及模型优化研究

针对攀钢热轧板厂二期改造后精轧设备和工艺条件的变化，对相关的工艺参数和极限进行了调整，从提高热轧产品尺寸精度和性能合格率、降低轧制能耗出发，对精轧工艺和数学模型进行了优化，在生产中取得了显著的效果。     

中厚板精轧轧制规程的负荷协调分配法及其动态调整

基于中厚板精轧过程的轧制特点，提出负荷协调分配法。该算法通过调整轧制力限制系数来调整约束条件使得最后道次的出口厚度与目标厚度的偏差小于给定误差，并同时获得优化的轧制规程。然后介绍如何根据轧件板形的变化来调整轧制规程。通过实例证明该算法及其动态调整方法适应性和灵活性很强，适合于在实时中厚板轧制过程中应用。     

遗传算法对热轧带钢精轧机组负荷分配BP网络参数的优化

为了克服了ＢＰ网络的局部收敛问题，提出了应用智能型优化方法－遗传算法对其网络参数进行优化的思想，在建立遗传－ＢＰ算法混合系统模型的基础上，以热轧带钢精轧机组负荷分配问题及实例进行了解析，计算结果表明了该算法的有效性。     

精轧区热轧带钢温度场的数值模拟

通过对带钢热连轧过程传热关系的分折，利用有限差分法建立了带钢三维温度场的数值计算模型。结合攀枝花钢铁集团公司热轧生产线的实际条件，利用该模型模拟了精轧区带钢的温度场，并与实泅结果进行了比较，验证了模型的可靠性。在此基础上，讨论了终轧厚度和轧制速度对带钢温度场的影响，为改进和优化轧制工艺提供了理论依据。     

热连轧精轧机组负荷分配的优化算法

基于功率成比例原则对带钢热连轧精轧机组进行负荷分配优化计算,建立了以 架出口厚度为未知量的非线性方程组,提出了一种新的简单求解方法－平衡迭代法,避免了导数计算和逆矩阵的求解。     

热连轧精轧机组轧制负荷分析

以太钢1549热连轧精轧机组为例,根据不同规格、材质带钢的实际轧制负荷分配情况阐述了精轧机组应如何合理的分配负荷。     

CSP精轧区带钢温度模型

 根据热轧带钢是否发生塑形变形,将CSP生产线精轧区划分为两类区域,并分别对这两类区域内影响带钢温度的因素进行了研究,从而建立了精轧区的带钢温度模型。运用Matlab的有约束非线性优化函数和origin的用户自定义回归选项等相关工具,分别优化得到了该温度模型的相关参数,从而确定了精轧区带钢温度模型。最后,利用所确定的模型对带钢的温度进行了预报,并与现场实测数据比较,结果表明,所确定的带钢温度模型具有较高的预报精度,适合CSP生产线的实际生产。     

热连轧带钢终轧温度预报模拟软件开发

 在传统热连轧精轧机组温降模型基础上,开发了带钢热连轧终轧温度预报软件。将带钢在中间辊道和精轧区内按主要冷却方式的不同划分为多个传热区域,并以带钢粗轧出口温度实测值为起点,依次累加计算带钢在精轧区内的温降。使用该软件计算的带钢恒速轧制温度预报结果与现场实测值吻合较好。     

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。     

Modelling the Temperature Distribution along the Length of Strip during Hot Rolling Process

Hot strip rolling process includes four main stages, which are reheating process, roughing and finishing process, laminar‐cooling process, and coiling process respectively. Temperature is the most sensitive parameter and has direct effect on the microstructural evolution and further the mechanical properties, and the accurate control of temperature guarantees the quality of products and homogeneity of properties along the strip length. However, for the conventional hot strip rolling process, thermal history along the strip length is very complex, the related temperature variation concerns air cooling, water cooling, heat transmission by roll contact, heat generation by deformation and friction. Based on the actual hot strip mill, the thermal models are established in this paper to simulate the temperature distribution along the whole strip length from the reheating furnace exit to the down coiler. Different interface heat transmission coefficients are selected for the scale breaking and spray water‐cooling process, and a self‐learning algorithm is thus employed to improve the calculation accuracy. This model is characterized as simple and fast, and convenient for on‐line/off‐line prediction of temperature. Finally the simulated results are verified by the on‐line temperature detection at typical points such as roughing exit (RT2), finishing exit (FT7) and coiling position (CT).     

精轧入口温度对Nb-V-Ti微合金钢组织的影响

在Gleeble-3800热模拟试验机上模拟了Nb-V-Ti微合金钢不同精轧入口温度的轧制和卷取过程,并观察了最终试样的显微组织。同时进行了多道次变形的模拟试验,通过平均流变应力分析了不同应变量下的未再结晶温度。结果表明,当精轧入口温度在未再结晶温度以上时,针状铁素体和多边形铁素体相对粗大;精轧入口温度在未再结晶温度以下时,随着精轧入口温度的降低,针状铁素体和多边形铁素体均逐渐细化。     

轴承钢GCr15棒材产品低温精轧的研究

采用国外引进的可实现低温精轧的生产线，对轴承钢GCr15棒材产品进行了低温精轧，通过低温精轧降低了网状碳化物级别，减少了球化退火时间。研究得到了低温精轧轧制GCr15时以控制网状碳化物级别为目标的轧制温度范围为750～840℃，轧后冷却温度范围为600～680℃，同时也研究得到了低温精轧轧制GCr15时以控制网状碳化物级别及减少球化退火时间为目标的轧制温度范围为750～800℃，轧后冷却温度范围为600～680℃。通过该研究网状碳化物级别达到了2级以下，球化退火时间由原18h减少到了11h。     

Theoretical Explanation of Uneven Transverse Temperature Distribution in Wide Thin Strip Rolling Process

 In this paper we propose a new theoretical thermo-mechanical explanation of the uneven transverse temperature distribution, along the width, for thin and wide hot rolled produced strip. In particular, we base our reasoning starting from the irregular pressure/friction distribution, that lead to an uneven heat generation. A 2-D mathematical model to calculate the transverse temperature distribution is presented, both to give a physical explanation to our problem, and to be used as an essential basis to build a correspondent FEM simulation model, in which heat loss and generation are both considered. Deformation and friction heat are both described in details, having a paramount importance in our reasoning. The heat generation problem is split into two parts, for a clearer and more logical analysis: one for the strip centre, and one for the sides, in correspondence of the temperature peak points at 100mm from the strip edge. Finally it is shown how our new theoretical model can lead to the exact interpretation of the measured uneven temperature distribution.     

Effect of Finish Rolling Temperature on Microstructure and Mechanical Properties of High Grade Pipeline Steel

The correlation among finish rolling temperature (FRT),microstructure and mechanical property of the high grade pipeline steel was investigated in this study.The microstructure of the steels with different finish rolling temperatures was observed with scanning electronic microscope (SEM) and transmission electronic microscope (TEM).The martensite/austenite (M/A) islands distribution was fixed by colour metallography,and the mechanical properties of the steels were tested with quasi-static tensile testing machine.The result shows that the fraction of M/A island increased with the finish rolling temperature decreasing,and when the finish rolling temperature is 800℃,the mechanical properties are the best.     

热连轧精轧过程中带材瞬态温度场的精确计算

基于热传导方程,考虑热连轧精轧区板带周期性地连续变形和连续冷却等复杂动态边界条件,利用有限差分法,在各机架变形区利用坐标映射关系建立三维瞬态温度场模型,在机架间非轧制区利用某横截面计算瞬态温度分布,这两种温度场模型互为条件,迭代求解。仿真结果表明,带材两侧边部有较大温差,易形成较大的局部热应力;带材越厚,压下量越大,带材高向温差越大,将会影响热连轧带材内部组织演变过程。仿真结果与实测数据吻合较好,表明模型能够精确预报热连轧精轧区板带的瞬态温度分布及终轧温度。