630t·m锻造操作机缸体热处理

630 t·m锻造操作机的缸体是操作机的关键部件.根据缸体的性能要求、毛坯尺寸以及设备能力制定了台车炉加热,喷雾淬火的热处理工艺,并制作了用于内孔通水冷却的专用附具.实践证明,生产的缸体完全符合设计要求.     

会员之窗

<正>二重集团公司成功浇注首套100万千瓦核电缸体(2011-3-1)100万千瓦核电缸体是二重集团公司重点产品之一。该缸体尺寸大、重量大、质量要求高,操作难度大。缸体不但上、下半单重都超过了100 t,而且上、下半各由大小不等的20余块砂芯组成。最大的砂芯高度近4 m,重量超过60 t。公司相关部门严格按照核文化理念及核电产品制造要求精心操作,确保了该缸体浇注成功。     

青岛华东机械签国产第一大操作机订单

日前，华东机械再传喜讯，为某大型核电设备厂设计制造一台600t·m操作机。这台操作机具有完全自主产权，可达到600t·m的夹持力，钳身中心距工作台面最高水平高度可达到5200ram，水平升降行程可达到3200mm，钳头旋转控制定位精度±1°，车体行走控制定位精度±8mm。达到国际领先水平，成为国产化第一大吨位操作机，打破600t·m操作机依赖进口的局面。     

柴油机缸体铸件残余应力测试及消除的研究

依据钻孔法测量铸件残余应力的基本原理,通过退火热处理,振动时效对消除柴油机缸体铸件残余应力测试结果表明:退火热处理可使缸体铸件残余应力下降87.61%,可满足该铸件的使用要求;而振动时效处理,可使残余应力下降27.4%,不能满足缸体铸件的使用要求.     

锻造操作机液压控制系统设计

锻造操作机是重大装备制造的关键设备。本文分析了1000kN/2500kN.m锻造操作机工艺参数要求,在此基础上设计了液压控制系统,并讨论了该系统的技术特点。     

9-12Cr缸体铸钢件热处理工艺与力学性能的研究

通过对超临界机组 9-1 2 Cr缸体铸钢材料的热处理工艺参数与力学性能的试验研究 ,优化出9-1 2 Cr缸体铸钢材料的最佳热处理工艺参数。     

国产化最大吨位600t·m全液压操作机在烟台顺利投产

2012年11月9日,青岛华东工程机械有限公司制作的首台国产化200t／600t·m全液压操作机在烟台台海玛努尔核电设备股份有限公司顺利投产。     

大型集成油路体加工

我厂10吨操作机液压系统采用集成油路体,在机床行业多采用叠加集成块式,而在锻造机械方而因为受强烈震动,采用块式集成油路体。 10吨操作机的四种集成油路体如图1所示。它的作用是把高压油泵打来的高压油通过其间被输送到各缸体和油马达,因此集成油路体的加工质量直接影响操作机的使用性能。     

大型灰铸铁汽轮机缸体的铸造工艺设计

针对大型HT250汽轮机缸体的壁厚差别大,尺寸精度和表面粗糙度要求高等诸多难点,进行了砂型和制芯工艺方案设计,对两种工艺方案进行了分析和选定,并就选定的造型工艺进行了浇口、冒口、冷铁工艺设计.结合缸体铸造工艺设计要求,给出了合箱、熔炼、浇注和热处理等工艺的控制要点.按照工艺方案成功地生产出了大型HT250汽轮机缸体铸件,铸件品质达到工艺设计要求.     

全铝发动机缸体的制备及缸套内表面处理工艺研究

采用高压压铸对离心铸造制备的自生初生Si、Mg_2Si颗粒增强Al-Si-Mg复合材料汽缸套-铝合金缸体进行压铸成型,获得全铝发动机缸体。分别采用传统油石珩磨工艺及"油石珩磨-SiC颗粒毛毡抛光法"对缸套内表面进行表面处理,并对缸体进行台架试验。结果表明:采用传统珩磨工艺处理后,缸套内表面粗糙度较高,无法达到设计要求;采用"油石珩磨-SiC颗粒毛毡抛光法"联合处理后,缸套内表面形成网纹效果良好,表面粗糙度Ra=0.32μm,符合企业技术规范。台架试验后在缸体内孔仅观察到摩擦印痕,发动机运行正常,其最大功率、最大转矩分别达到了8.18 kW,10.77 N·m。     

大型焊接容器局部热处理防畸变工装优化设计

采用有限元方法对大型压力容器局部热处理畸变进行模拟,基于热处理最大畸变量,初步设计了工装的最佳尺寸,分析了不同直径和壁厚对筒体局部热处理畸变量的影响,得到了适用于不同筒体尺寸的最佳防畸变工装数量。结果表明,支撑台宽度0.2 m、支撑柱直径ø4 cm为最佳的防畸变工装尺寸。筒体的直径越大,热处理畸变量也越大;筒体壁厚越厚,热处理畸变量越小;防畸变工装数量越多,热处理畸变量越小。     

热处理对TA2合金表面激光熔覆Ti2SC/TiS涂层组织和力学性能的影响

目的对激光熔覆自润滑耐磨涂层进行热处理,获得具有较好摩擦学性能的复合涂层。方法采用激光熔覆技术在TA2合金表面熔覆40%Ti-25.2%TiC-34.8%WS_2复合粉末制备自润滑耐磨复合涂层。将涂层置于500℃真空中分别保温1、2 h,采用扫描电镜(SEM)、X射线衍射仪(XRD)、能谱仪(EDS)、显微硬度计、摩擦磨损试验机以及原子力显微镜(AFM)系统地分析了热处理前后涂层的物相、组织、显微硬度及摩擦学性能。结果未经过热处理和经过热处理涂层的主要物相均为α-Ti、(Ti,W)C_(1-x)、TiC、Ti_2SC和TiS。相比未经热处理涂层的显微硬度(1049.8 HV_(0.5)),经过热处理1 h和2 h涂层的显微硬度(1143.3 HV_(0.5)和1162.7 HV_(0.5))有所上升。热处理1 h和2 h涂层的摩擦系数和磨损率分别为0.29和6.66×10~(-5) mm~3/(N·m)以及0.29和5.65×10~(-5) mm~3/(N·m),比未热处理涂层(0.32和18.92×10~(-5) mm~3/(N·m))的耐磨减摩性能有所提升。经过热处理1 h和2 h涂层的磨损机理均主要表现为磨粒磨损,未经热处理涂层的磨损机理主要为塑性变形和粘着磨损。结论相比未经热处理的涂层,经过热处理1 h和2 h的涂层显微硬度有所升高,摩擦学性能得到提升,但在两种热处理时间条件下,涂层显微硬度和摩擦学性能变化较小。     

基于线性扩张状态观测器的机械臂变负载滑模控制

大型串联机械臂液压控制系统存在变负载及外干扰问题,机械臂不同工作姿态的等效质量会造成液压缸系统固有频率变化,影响系统动态特性,为此提出一种基于线性扩张状态观测器的滑动模态控制策略(LESOSMC)。以破拆机器人机械臂为研究对象,仿真试验结果表明:LESOSMC在机械臂处于不同姿态时,保持了很好的动态特性和稳态精度,对周期正弦信号也具有良好的跟踪性能。LESOSMC在机械臂变负载控制中具有良好的鲁棒性,满足重载液压机械臂关节位置控制的要求,为解决液压重载机械臂关节液压缸的位置控制提供了有效的工程方法。     

液压支架油缸内壁缺陷修复机械臂的运动学分析与仿真

针对矿用液压支架油缸内壁局部缺陷修复,设计一种能深入液压支架油缸筒内进行内壁修复的焊接机械臂。基于改进D-H参数建模方法,对设计的内表面修复焊接机械臂进行运动学建模,并求解了内表面修复焊接机械臂的正、逆运动学。借助MATLAB软件,采用蒙特卡洛法,对该焊接机械臂的有效工作空间进行了仿真分析,利用Robotics Toolbox工具箱对油缸内壁缺陷修复机械臂进行关节轨迹规划,通过仿真得到各关节的角位移、角速度、角加速度曲线。仿真结果表明：该机械臂运行平稳,轨迹连续,满足运动学要求。     

1000kN/2500kNm锻造操作机吊挂装置仿真研究

基于动力学系统分析软件ADAMS,建立了1000kN/2500kNm锻造操作机吊挂装置的虚拟样机模型,分析了上升和倾斜运动时各部件的运动及受力情况。结果表明,钳杆最大平升高度、最大上倾和下倾角度、平升缸和倾斜缸静平衡驱动力均满足设计要求,仿真结果可以为锻造操作机的设计制造提供指导。     

Optimising the T6 heat treatment for gravity cast AlSi7MgCu0.5 alloy V8 cylinder heads

Alternatives to the Standard T6 heat treatment that relied on a 5-h solution heat treatment at 490 °C were investigated in effort to reduce the heat treatment cycle time for the manufacture of AlSi7MgCu0.5 alloy V8 cylinder heads without sacrificing the mechanical properties while providing extra capacity in the heat treatment plant. The optimum T6 heat treatment process was identified to be a SHT at 545 °C for 1 h followed by ageing treatment at 180 °C for 3 h. Mechanical properties of the cylinder heads thus manufactured were markedly superior while the total heat treatment duration was reduced by 2.5 h with respect to the Standard heat treatment. This implied a capacity increase of %61 and rendered the undertaking of a major customer order possible.     

Investigation of thermal behavior on cylinder liner during its boring process

Research was conducted on the effect of cutting conditions on temperature rise of cylinder liner during cylinder-boring process. A finite element method (FEM) model was developed to confirm suitable cutting conditions by predicting the temperature distribution in a cylinder liner and thermal expansion of the cylinder liner. To analyze the temperature distribution in the cylinder liner during machining, the partition of the total heat generated during machining which flows into the cylinder liner has to be investigated. A method combining experiment with analysis, called an “inverse heat transfer method”, was used to estimate the heat percentage flowing to the cylinder liner in this paper. To capture the required data for the inverse heat transfer method, sets of dry and wet boring experiments were conducted to estimate the temperature distribution in the cylinder liner wall and the cutting force during machining. The influence of the cutting conditions (for example: cutting speed, feed rate, depth of cut, cutting fluid) on the cutting force and temperature distribution in a cylinder during machining was investigated, and the heat partition flowing to the workpiece under various cutting conditions (especially, under high-speed cutting, with a maximum cutting speed up to 900 m/min) was then determined. A three-dimensional FEM analysis model was developed to simulate the temperature distribution in the cylinder liner and thermal expansion of the cylinder liner during machining. Then, the suitable cutting conditions in cylinder boring were confirmed by FEM analysis. To investigate the influence of the air cooling on the temperature distribution in the cylinder liner after machining, the change of temperature distribution in the cylinder liner under air cooling was predicted.     

Influence of heat input and post-weld heat treatment on boiler steel P91 (9Cr–1Mo–V–Nb) weld joints Part 2 – Mechanical properties

Abstract

Three thick pipes of modified 9Cr–1Mo steel were welded using three different levels of heat inputs: low heat input 1·1 kJ mm^?1, medium heat input 2·3 kJ mm^?1 and high heat input 3·16 kJ mm^?1. Two types of heat treatments were employed, namely subcritical post-weld heat treatment and normalising/tempering treatment. The influence of heat input and post-weld heat treatment on the microstructure of boiler steel P91weld joints has been investigated in the previous paper. In the present work hardness, tensile, impact toughness and stress rupture properties were evaluated. Our results show a great influence of heat input and heat treatment on mechanical properties. The best combination of properties was obtained in low to medium range of heat input, between 1 and 2·8 kJ mm^?1 for both treatments and a 90% increase in time to rupture was observed for normalising/tempering treatment compared to subcritical post-weld treatment.     

锻造操作机钳杆机构的动态分析

采用SolidWorks和ADAMS软件建立了锻造操作机的虚拟样机模型,用虚拟样机技术对钳杆机构进行了仿真分析,精确得出操作机设计所需的重要参数,计算了夹紧力的大小和驱动力矩的变化规律,合理地减小了夹紧缸的直径,为操作机的其他部分提供了更多的设计空间。在仿真结果的基础上,采用ANSYS软件对钳臂进行了优化设计,降低了节点的最大应力值。