转炉炉壳的变形分析及延长炉壳寿命的措施

分析了转炉炉壳变形的原因,提出了采用炉壳强化冷却的措施来控制炉壳变形,延长炉壳寿命,实现转炉炉壳的长寿化。     

转炉炉壳变形及处理措施的浅析

结合包钢CSP210 t转炉的托圈和炉壳修配改过程,借鉴国内外其它钢厂的宝贵经验,针对转炉炉壳蠕变变形问题,提出通过炉壳整形、改善炉壳材质及强化冷却炉壳来控制炉壳变形,保证炉壳与托圈的间隙,以提高炉壳使用寿命.     

转炉炉壳变形与对策

在分析转炉炉壳严重变形问题的基础上,提出了采用炉壳整形、改善炉壳材质以及强化炉壳冷却系统的措施来控制炉壳变形,并具体分析了这些措施的优缺点.     

转炉炉壳的蠕变变形模型

转炉炉衬采用镁碳砖后，炉壳温度可达450℃或更高，造成炉壳蠕变变形，通过转炉炉壳蠕变变形影响因素的分析和ANSYS软件建立了炉壳蠕变变形的计算模型，有限元模拟计算结果与现场测量值基本吻合。     

宝钢转炉炉壳长寿实践

为了提高炉龄,高导热镁碳砖在转炉上得到了普遍使用,钢水向炉壳的热传导由此也大幅提升,使炉壳表面温度维持在高温区域,从而引起了转炉炉壳变形加剧,导致转炉炉壳使用寿命缩短,影响正常安全生产.概述了宝钢在转炉炉壳长寿方面所做的一些工作,包括炉壳整形、耐蠕变的炉壳钢板研制及炉壳冷却技术的开发,并讨论了这些技术的效果和局限性.     

转炉炉壳变形及其控制

大型转炉用镁碳砖炉衬后，炉壳温度可达４７０℃或更高，造成炉壳蠕变而变形。研究了转炉炉壳变形的状态及规律，分析了炉体机械应力、温度应力及膨胀应力。并通过蠕变实验预测炉壳的残余寿命。还介绍了改善及控制炉壳变形的整形技术和冷却技术。     

转炉炉壳采用汽雾冷却时的瞬态温度场及应力场研究

大型转炉用镁碳砖炉衬后,炉壳温度急剧增加,已超出炉壳材料的蠕变温度,造成炉壳蠕变变形.采用汽雾冷却技术可对转炉炉壳实施温度控制.利用有限元法模拟了炉壳实施汽雾冷却的瞬态温度场和炉壳瞬态应力场.     

控制转炉炉壳蠕变变形

转炉采用镁碳砖炉衬后，炉壳温度急剧增加，炉壳的局部区域会发生永久变形。分析认为：炉壳的永久变形是由于蠕变变形引起，而不是塑性变形引起，给出了影响蠕变变形的因素，指出了控制炉壳蠕变变形的策略。     

宝钢300t转炉新炉型炉壳有限元法强度分析研究

对宝钢 30 0t转炉新炉型炉壳进行了有限元强度分析 ,计算结果表明 ,该炉壳在机械荷载 (炉体自重和钢水重力 )、温度荷载及热膨胀压力等联合作用下所产生的综合应力 ,在转炉炉壳的许用应力允许值之内 ;其所产生的变形 ,也在新炉型炉壳的刚度设计范围内。     

宝钢300t转炉新炉型壳有限元法强度分析研究

对宝钢３００ｔ转炉新炉型炉壳进行了有限元强度分析,计算结果表明,该炉壳在机械荷载（炉体自重和钢水重力）、温度荷载及热膨胀压力等联合作用下所产生的综合应力,在转炉炉壳的许用应力允许值之内;其所产生的变形,也在新炉型炉壳的刚度设计范围内。     

宝钢300t转炉炉壳的整形效果及分析

在分析宝钢第一炼钢厂转炉炉壳整形必要性的基础上，对转炉炉壳整形的实际效果进行了分析，证明火工校正结合机械牵引的整形方法可以较好地增加炉壳与托圈之间的间隙。     

ASSEL轧管机钢管变形特征分析

分析了不同Ｄ／Ｓ值的厚,中,薄壁管在ＡＳＳＥＬ轧管机上的螺旋变形特征和壁厚精度。分析表明,随轧后荒管Ｄ／Ｓ值的增大,壁厚精度下降。ＡＳＳＥＬ轧管机具有台肩集中变形,碾轧段壁厚增厚等特点。     

IF钢热轧薄板边部翘皮缺陷的产生原因及机制

 观察了IF钢热轧薄板边部翘皮缺陷的微观组织与晶界状态,分析了其形成原因和内在机制。结果表明,边部翘皮缺陷具有以下几个特征：在横截面上,翘皮表现为深度约40μm的微裂缝;裂缝附近组织具有混晶、形变的特征;裂缝内存在氧化铁皮,附近存在Al2O3-MnO-TiO2的复合氧化质点。微观组织分析与工业验证试验均表明,IF钢热轧薄板边部翘皮缺陷主要是由于中间坯边角部温度过低、热轧过程中发生不均匀变形导致。     

Heat Transfer and Deformation Behavior of Shell Solidification in Wide and Thick Slab Continuous Casting Mold

With the considerations of the behaviors of shell deformation, mold flux film and air gap dynamic distribution in shell/mold gap, a two dimensional slice-travel transient thermo-mechanical coupled model of simulation shell solidification in wide and thick slab continuous casting mold was developed by using the commercial program ANSYS. The evolutions of strand-mold system thermal behaviors, including the air gap formation and the mold flux film dynamical distribution in shell/mold gap and shell temperature field, and the evolutions of shell deformation and stress distribution of peritectic steel solidified in a 2120 mm wide and 266 mm thick slab continuous casting mold were analyzed. The results show that the air gap formation and the thick mold flux film distribution mainly concentrate in the regions 0–21 mm and 0–7 mm, 0–120 mm and 0–100 mm off the shell wide and narrow faces corners, and thus the hot spots are given rise to form in the regions 15–55 mm and 15–50 mm off the shell wide and narrow face corners. The shell server deformation occurs in the off-corners in the middle and lower parts of the mold. The stress evolution in shell surface is tensile stress, while that in shell solidification front is compressive stress.     

Postbuckling of Shear Deformable Laminated Cylindrical Shells

A postbuckling analysis is presented for a shear deformable laminated cylindrical shell of finite length subjected to compressive axial loads. The governing equations are based on Reddy’s higher-order shear deformation shell theory with a von Kármán–Donnell type of kinematic nonlinearity. The nonlinear prebuckling deformations and initial geometric imperfections of the shell are both taken into account. A boundary layer theory of shell buckling, which includes the effects of nonlinear prebuckling deformations, large deflections in the postbuckling range, and initial geometric imperfections of the shell, is extended to the case of shear deformable laminated cylindrical shells under axial compression. A singular perturbation technique is employed to determine the buckling loads and postbuckling equilibrium paths. The numerical illustrations concern the postbuckling response of perfect and imperfect, unstiffened or stiffened, moderately thick, cross-ply laminated cylindrical shells. The effects of transverse shear deformation, shell geometric parameters, total number of plies, fiber orientation, and initial geometric imperfections are studied.     

Hot Expansion of a Thin-Walled Cylindrical Shell of Porous Material

A system of equations describing the hot expansion of a thin-walled cylindrical shell of porous material by internal pressure was obtained. The solution was based on one of the simplest creep theories, namely, work hardening theory. The radial, meridial, and volume rates of creep deformation were calculated in comparison with the basic circumferential deformation rate of the shell. The numerical results were obtained by considering a process of stepwise loading of the shell. It was established that porosity in the material decreases the limiting value of internal pressure of the shell.     

Principles in cast rolling with liquid core of thin slab continuous casting

Dynamic rolling deformation behavior of continuously cast slabs with liquid core is studied with the aid of the thermomechanically coupled finite element method (FEM) of elastic-plasticity. The effects of shell thickness and related height reduction on the longitudinal tensile strain of strand are analyzed from a simplified three-dimensional (3-D) model. The results show that the longitudinal tensile deformation can be omitted for strands with thin shell, but it cannot be neglected for those with thick shell. A new concept of inward pushing or pushing into the liquid core is put forward based on the analysis, which leads to a reasonable explanation and better understanding of the liquid core cast-rolling processes in the present Inline Strip Production (ISP) thin slab casting.