车轮淬火加热过程温度场的数值模拟

根据马钢车轮淬火加热炉的实际状况,建立了车轮淬火加热过程温度场计算模型。应用该模型对某规格车轮的淬火加热过程温度场进行了模拟,并应用在线测温系统对该规格车轮淬火加热过程的温度变化进行了实测,结果与实测结果吻合较好。通过模拟发现,该规格车轮现行加热时间过长,有很大的压缩空间。     

锆板真空炉退火特点及均热性研究

针对真空热处理过程中,工件的加热速度明显滞后于炉膛升温速度的现象,采用实测法通过对3m真空退火炉热处理纯锆板时工件温度与炉膛温度的研究,经分析计算得出锆板在该炉中加热的透热系数及周期作业时间,为后续热处理工艺的制定提供了参考依据.     

曲轴圆角感应加热淬火新技术简介

我国某内燃机制造厂消化引进国外曲轴圆角感应加热淬火新技术,自行设计制造出回线型半圈圆角淬火感应器,用于曲轴圆角感应加热淬火强化。这种感应器在曲轴旋转时对轴颈分别进行加热、加热到淬火温度时     

GCr15钢制轧辊的返新热处理工艺

本文通过对GCr15钢制轧辊返新热处理工艺的生产总结,整理出冷轧辊淬火加热的保温时间,双液淬火冷却剂的选用,在冷却液中的冷却时间等工艺要素.     

不同锭型及热负荷下均热炉内对流换热系数的模拟分析

均热炉是钢锭轧前加热过程的主要设备,其炉内的对流换热对于钢锭的加热过程有着很大的影响。文中以均热炉内对流换热过程为研究对象,通过对模拟研究得到了不同锭型在不同热负荷下加热过程中表面对流换热系数的变化情况,为钢锭加热过程工艺优化提供了基础。     

30～50千赫可控硅超音频装置在感应加热中的应用

一、超音频电源在感应加热中的应用 随着感应加热热处理工艺的发展,对感应加热电源的频率和功率要求越来越多、分得也越来越细,不同的机械另件表面热处理和透热需要不同的电流频率和功率。 1.齿轮感应加热淬火热处理 通过一系列的理论研究得出的结果是:对一定模数齿轮来说要获得沿齿廓的均匀淬火层,其最佳电流频率由下式确定: f=250/M~2千赫或f=330/M~2(在600°～700℃进行予热)式中M—齿轮模数。 所以当齿轮模数为2—5mm时由计算可得淬火加热最佳频率为10—62.5kc或13.2—82.5kc(600°—700℃进行予热)。 2.凸轮轴、凸轮淬火最佳频率按公式f=3800/r~2计算。(其中r—凸轮尖部曲率最小半径,厘米)对195型柴油机凸轮尖部曲率半径为0.35cm,其感应加热淬火最佳工作频率为32kc左右。     

曲轴圆角感应加热淬火新技术简介

我国某内燃机制造厂消化引进国外曲轴圆角感应加热淬火新技术,自行设计制造出回线型半圈圆角淬火感应器,用于曲轴圆角感应加热淬火强化。这种感应器在曲轴旋转时对轴颈分别进行加热、加热到淬火温度时感应器自动上升,淬火机床将被加热曲轴翻转进入槽中,浸液喷冷淬火,同时相邻的另一根曲轴便进入加热位置,感应器下降至主轴颈,进行加热,如此循环工作下去。采用这种回线型半圈感应器加热,由于感应器与轴颈之间的间隙较小,且有效圈上装有导磁体,其电热转换效率较老式整圈感     

电炉文摘WJ89973～89996

本文详细研究了拖拉机零件淬火和回火用感应加热设备的应用效果。作者以拖拉机半轴、原动轴和圆柱齿轮三种零件为例,分别叙述了它们感应加热工艺特点和加热效果。还着重介绍了采用感应加热淬火和回火的自动操纵零件装卸过程的自动淬火机床的结构和工作过     

在箱式滴控炉中进行GCr15钢精密偶件的热处理

本文介绍了利用UNIC箱式滴控炉对GCr15钢精密偶件进行淬火所取得的效果,说明了偶件在可控气氛保护下加热淬火的优越性。并对如何正确合理地制定箱式滴控炉偶件热处理工艺参数进行了论述,对热处理过程中应注意的问题和出现的现象,进行了讨论说明。     

取消铸造隔板静叶调质处理研究

铸造隔板使用的静叶其技术要求是采用淬火，回火工艺，但在铸件浇注过程中，静叶被加热，静叶在产品上的机械性能将改变，为了弄清这一情况，对隔板在浇注过程静叶温度变化进行了测试，得出静叶被加热温度与隔板汽道泥芯体积的相互关系，并根据测试结果提出了为减少叶片被拉裂和降低制造成本取消淬火，回火工艺的建议。     

加热炉计算机控制系统的研究与开发(Ⅳ)——钢坯加热控制

以加热炉数学模型数据库与工人操作经验为基础,开发与研制轧钢加热炉热过程计算机控制系统,构造钢坏加热、待轧、待温过程控制模块,实现钢坏优化加热过程,在包钢带钢厂生产实践中取得了较好的经济效益。     

Analysis of Entropy Generation during the Convective Quenching of a Cluster of Balls

An entropy generation analysis is carried out for convective quenching of cluster of hot balls in a pool of three common quenchants (molten salt, water and oil). The formulation is based on the conservation principle in Eulerian framework following a two-fluid approach and clearly indicates the contribution due to thermal irreversibility as a result of finite temperature gradient and that due to viscous effect arising out of drag. The time averaged normalized entropy generation is used to find the most suitable injection velocity in the quenching process for molten salt. The quenching process is optimized by using the entropy generation parameter.     

Properties of the oxide compound spherulites,obtained from the melt in a solar furnace

The properties of the spherulites based on aluminum oxide, mullite, and zirconium dioxide that are obtained by melting and subsequent quenching in a 1000 kW solar furnace are studied. These spherulites are hollow. The thickness of the wall of the sphere is determined by the quenching rate. The microstructure of the spherulites that are based on aluminum oxide consists of crystallites of cubic form, the microstructure of the spherulites that are based on zirconium dioxide consists of micrograins of rounded form. The hardness and the elastic properties exceed the known values for the electrically melted materials that are based on corundum and zirconium dioxide.     

基于ANSYS的锻件感应加热温度场的数值模拟研究

针对感应加热过程中工件温度难以测量的问题,应用电磁学和传热学基本理论,建立了锻铸坯料电磁场和温度场分布的数学模型,运用ANSYS软件对感应加热过程温度分布进行变参数研究,为揭示铸坯感应加热过程的规律、优化工艺参数提供理论依据。     

电热水器梯度加热改进方案的仿真模拟与试验研究

针对电热水器梯度加热过程中,出水温度不稳定影响洗浴舒适性的问题,通过建立数学物理模型及仿真模拟,分析获得了梯度加热时出水温度波动的原因。以此为基础,提出梯度加热改进方案,并利用仿真模拟对改进方案进行分析。仿真研究结果表明,改进方案可解决原型机在梯度加热开启时的温度跃升现象。同时,基于优选方案,搭建试验系统,对改进后的热水器进行了试验测试。试验研究结果表明,梯度加热功能开启时,出水温度较为平缓,无突变现象,实现了电热水器流动换热过程的优化。     

气氛烧结炉温度场的仿真研究

对以石墨作为加热体的气氛烧结炉的仿真加热过程进行了研究,运用有限元分析的思想,通过仿真进行分析加热因子对加热炉加热过程中温度变化的影响,得出受热工件温度随时间变化的曲线,模拟出接近真实的温度场分布,对现实中的工业加热提供有效的参考。     

钢锭优化加热计算机控制系统

以钢锭热过程一维无限长圆筒控制数学模型为基础，开发了均热炉群钢锭优化计算机控制系统，并采用美国爱克新公司生产的ＣＩＭ－ＰＡＣ分布式控制系统在马鞍山钢铁公司初轧厂实现了均热炉群钢锭生产过程的在线优化控制和管理。     

Experimental investigations of the quenching phenomena for hemispherical downward facing convex surfaces with narrow gaps

To investigate a gap cooling mechanism between a corium and a reactor pressure vessel, quenching phenomena of hemispherical downward facing surfaces with narrow gaps with respect to wall heating conditions have been investigated experimentally. The experiments were performed with a hemispherical gap thickness of 1 and 2 mm, and the wall heating conditions, that is, with and without an external wall heating. That is, the internal vessel (or both internal and external vessels) was heated up to 450 °C, and distilled water was supplied to the hemispherical gap region, and then the temporal histories of the internal and the external vessels were measured by the thermocouples embedded in the internal and the external vessels. From the interpretations of the wall temperature and the heat flux history, it was found that the quenching process was changed by the wall heating conditions. If the external wall was not heated, then the internal vessel wall was stably quenched from the bottom to the top region because the coolant water was supplied to the gap region through the cold external wall. However, if both the internal wall and the external wall were heated, then the quenching phenomena were more complicated and slower as the gap thickness decreased, because the coolant supply to the gap was restricted.     

某天然气净化厂供热系统设计

某天然气净化厂需设置一套供热系统,为工艺装置及冬季采暖提供热负荷.根据热用户对用热参数的要求,可采用蒸汽锅炉供热系统或导热油加热炉供热系统.从投资、运行、管理及维护等方面对两种供热系统进行方案比较.导热油加热炉供热系统具有以下优点:运行和维护费用低、不消耗水资源、可露天布置、导热油倾点低,适合当地严寒气象条件.推荐选用...     

Crystal growth of CuGaxIn1−xSe2 by horizontal bridgman method

Single crystals of CuGa_xIn_1−xSe₂ were grown from stoichiometric melt by horizontal Bridgman method. An non-contact carbon coating method was used to avoid sticking between quartz ampoule and the melt. The composition variations along the as-grown ingots were studied as a function of Ga content. X-ray powder diffraction measurements were carried out to determine the lattice constants.