回转窑焊接工艺设计

本文介绍了水泥工业用回转窑筒体的焊接工艺,由于其体积大以及各段节承担任务的不同,窑体主要由几部分厚度不同的筒节组合而成,因此,窑体的焊接是一个关键环节。焊接工艺设计时应遵循水泥工业用回转窑国家标准的规定,然后结合实际情况,确定筒节的节数,以及焊缝的条数,先设计出各个筒节的焊接工艺,再设计出两筒节间的组合焊接工艺,并合理安排焊缝的相对位置。     

快中子反应推堆容器筒节焊接的模拟分析

本文通过对快中子反应堆堆容器筒节焊接的有限元模拟分析,使设计师了解到了快中子反应堆堆容器筒节焊接过程中的应力变化规律。     

快中子反应堆堆容器筒节焊接的模拟分析

本文通过对快中子反应堆堆容器筒节焊接的有限元模拟分析，使设计师了解到快中子反应堆堆容器筒节焊接过程中的应力变化规律。     

板焊热壁加氢反应器的制造

介绍板焊热壁加氢反应器的壳体材料的化学成分，反应器壳体的分段，筒节的冷弯，筒节的纵焊缝的焊接，不锈钢层的堆焊，筒节的环焊缝的焊接，最终焊后热处理。     

高温高压飞灰过滤器厚壁大直径筒节的制造

介绍了高温高压飞灰过滤器筒节结构特点，并对筒节的滚制、组对及其焊接防变形措施进行了重点阐述。     

快装锅炉前管板内环缝埋弧自动焊的工艺装备

快装锅炉本体构结见图1。原焊接工序是:先将筒体与后管板装配点固,采用埋弧自动焊在转台上焊接内环缝和外环缝,然后再装配点固前管板。此时因探臂已无法伸入筒体,因此只能采用手工焊接内环缝。前管板内环缝采用手工焊,为保证外环缝采用埋弧自动焊焊接时不烧穿、焊漏,需要开较大的坡口,因此手工焊工作量很大(需焊四遍以上),劳动强度也大。锅炉     

大型焊接筒节切削刀具的振动特性

为了研究大型焊接筒节切削过程中刀具的振动特性,首先,对切削振动的产生机理进行分析,建立大型焊接筒节切削过程动力学模型;然后,通过参照实际生产加工条件进行切削振动模拟实验,结合模型变化规律修正法对振动模型进行修正,从而验证模型在实际应用中对切削振动预测的可行性与精度保持性;最后,确定大型焊接筒节切削振动产生的临界条件,为进一步研究大型结构不稳定零件加工过程的振动规律提供理论支撑。     

大型筒体焊接操作架的设计与改进

正1.概述筒体是球磨机、回转窑的主要部件。由于这些筒体达到了?3 000~?6 000mm、长度达到了10 000~20 000mm,因此筒体由若干个筒节采用埋弧焊方法组焊而成。这种方法焊接筒体环缝的特点是焊嘴固定不动,通过筒体在转胎上匀速旋转完成焊接。故焊接过程需采用焊接操作架夹具完成。由于以往的焊接操作架是用槽钢组焊而成,直接放在地     

风电塔筒筒节吊装转运过程临时焊缝强度研究

风电塔筒筒节在卷圆机上卷制后,由于空间受限仅能在卷制钢板对接接口的内侧两边焊接临时焊缝,然后吊装转运到滚轮架上进行正式焊接。在吊装转运过程中临时焊缝经常出现断裂的情况,临时焊缝断裂可导致筒节母材受损,且存在较大安全隐患。针对这种情况,文中采用有限元法对吊装过程中的无焊缝筒节进行受力分析,通过分析得知筒节相对过圆心垂直面不同角度位置受力不同,在角度为33°、130°、-33°、-130°时应力最小约为0 MPa。另外,将临时焊缝放置于应力最小位置,分析筒节不同直径、不同厚度以及不同筒长对临时焊缝处应力的影响,临时焊缝处等效应力随筒节直径增大而增大,随厚度减小先减小而后增大,随筒节长度变化不大。     

搅拌运输车进料斗漏料问题分析及解决方案

搅拌运输车进料斗与车架、搅拌筒两个部件存在关联性装配关系,而车架与搅拌筒为大型结构件,不可避免存在焊接误差,由此导致进料斗装配精度很难保证,从而出现漏料问题。介绍漏料的具体原因并给出解决方案,实现了搅拌车进料斗漏料问题零反馈,取得了良好的使用效果。     

Principle and Simulation of Fixture Configuration Design for Sheet Metal Assembly with Laser Welding, Part 1: Finite-Element Modelling and a Prediction and Correction Method

The quality of the stamping process has a direct effect on laser welded sheet metal assembly. The fixture plays an important role in the satisfactory metal fit-up that laser welding requires. The traditional "3-2-1" locating scheme will no longer suffice for the deformable laser sheet metal assembly process. Because of the often poor stamping quality, a complex die fixture has to be employed to meet the metal fit-up requirements. The die fixture corresponds to an "infinite-2-1" locating scheme where the tooling cost is very high and yet lacks flexibility. This limits the application of laser welding. In this paper, a new locating scheme with both total locating and direct locating for welds is proposed. A total locating scheme is used to locate the overall assembly, and a direct locating scheme is used to locate the weld location, which is critical for ensuring correct metal fit-up. A finite-element model and a prediction and correction method for the direct locator configuration are developed in this paper. A case study is used to show that the proposed method is effective for sheet metal assembly for laser welding.     

Electromagnetic arc path control in robot plasma welding

Arc welding has always presented a challenge to robot operation. Variations in joint fit-up, positional welding requirements and the high levels of welder skill demanded by transient changes in operating conditions are just some of the variables with which any arc welding robot must cope. The article examines how an inertia-less high-frequency weaving technique using a novel deflector system can solve many of these problems even for high speed seam tracking.     

Weld Pattern Design for Sheet Metal Laser Welding Considering Fixturing Quality

In sheet metal assembly by laser welding, metal fit-up is an important specification for achieving welding quality. The fixture plays an important role in satisfying the intimate metal fit-up that laser weld requires. The fixturing quality for sheet metal laser welding is directly related to the assembly weld patterns used (weld location, weld length, etc.). The design of assembly weld patterns is a critical phase in the fixture design cycle. Traditionally, the determination of the weld pattern is based on the designer’s experience. Because of this it is quite easy to cause unexpected deviations from the assembly weld quality requirements. In this study, a new computer-aided design approach for the assembly weld pattern is developed, where the sources of variation in the weld areas of the parts are considered in detail. Using this approach, the weld location and the weld length obtained are much more reasonable and cost-justified. A simple example and a case study show that the approach presented for assembly weld pattern design can reasonably meet the fixturing quality requirements.     

Principle and Simulation of Fixture Configuration Design for Sheet Metal Assembly with Laser Welding, Part 2: Optimal Configuration Design with Genetic Algorithm

A fixture plays a key role in ensuring proper metal fit-up in sheet metal assembly with laser welding. In this paper, an optimal fixture configuration design model is proposed based on a new locating scheme which includes both total locating and direct locating on welds. In this model, both the number and the location of the concerned locators are taken as objectives. The proposed prediction and correction method is used for determining the number of direct locators, and a pattern sorting method is developed for determining the number of total locators. Considering the degree of metal fit-up (DMF) to be a fuzzy quantity, a feasible evaluation criterion of DMF is also developed using a fuzzy synthesis evaluation method. A powerful optimisation technique – genetic algorithm – is employed as the optimisation procedure. A case study is presented which demonstrates the effectiveness of the optimal model, and the degree of metal fit-up can be improved compared to the initial locating scheme.     

Stability of the friction stir welding process in presence of workpiece mating variations

This paper explores common process variations encountered in friction stir welding (FSW) and the limits to which acceptable joint strength is maintained while welding with a robotic FSW system. Part fit-up and mating variations are common in manufacturing, yet the limits to which a friction stir welding process can weld without major process adjustment are unclear. The effects on joint strength and mechanical properties of several of the most common mating variations (i.e., faying surface gap, misalignment, mismatch, etc.) are experimentally determined as individual effects as well as among common welding parameters. Experimental results on 5-mm-thick aluminum alloy 5083-H111 show that ultimate tensile strength, yield strength, and elongation begin to decrease from nominal weld conditions when either the tool offset distance from weld centerline or gap in abutted plates exceeds 25% of the average pin diameter (6?mm). In addition, vertical plate mismatch and lack of penetration can be tolerated up to 2.5% and 10%, respectively, before adverse effects on mechanical properties are observed. The work also indicates that of all the mating variations tested in this study, tool misalignment, followed by travel angle, has the most significant effect on the measured joint strength. Process stability testing has shown that the FSW process is able to endure part fit-up and mating variations within a defined tolerance, giving the practitioner an awareness of how well stock workpiece tolerances must be controlled before joint strength is adversely effected.     

Development of Adaptive Fill Control for Multitorch Multipass Submerged Arc Welding

A significant portion of the total manufacturing time for a pipe fabrication process is spent on the welding following the primary machining and fit-up processes. To achieve a reliable weld bead appearance, automatic seam tracking and adaptive control to fill the groove are urgently required. For seam tracking in the welding processes, vision sensors have been successfully applied. However, the adaptive filling control for a multitorch system for the appropriate welded area has not yet been implemented in the area of submerged arc welding (SAW). This paper describes several advances in sensor and process control techniques for applications in SAW which combine to give a fully automatic system capable of controlling and adapting the overall welding process. This technology has been used in longitudinal and spiral pipe mills and in pressure vessel production.     

薄壁钛合金舱体制造技术

探讨了薄壁钛合金舱体的制造工艺技术,舱体采用典型的焊接结构,主要零件是蒙皮、法兰端框、环状加强框、口框等。采用热成型、数控机加工和多种焊接方式的组合制造方法,为设计提供了一种完全不同于铸造的钛合金零组件制造工艺。这种工艺方法完全能够制造出满足设计要求的高强度钛合金舱体,为型号研制提供了一种成熟、可靠、高效的制造工艺方法。通过产品焊接工艺试验,完成了舱体的研制,产品质量稳定可靠,满足了产品设计需求。     

φ800mm鲁奇式加压气化炉壳体的焊接

介绍了先进的鲁奇炉代表型MARK#Ⅳ/4型φ3 800 mm鲁奇式加压气化炉壳体的焊接工艺及相关要求。根据产品的结构特点确定试验方案,在试验的基础上针对产品制造过程中的一些疑难问题进行方案论证和工艺攻关。制订了科学合理的焊接工艺方案,采取一系列措施保证产品质量和控制焊接变形,实现壳体纵环缝焊接采用窄间隙埋弧焊自动跟踪压道焊工艺。成功地解决了鲁奇式φ3 800 mm加压气化炉壳体焊接在质量性能、控制焊接变形等方面存在的难题,获得了满意的焊接效果。该项目的研制成功为承制大型疲劳容器和耐高温、高压的机械传动设备积累了宝贵的经验。     

连铸辊套φ150/φ170表面耐磨层堆焊工艺

连铸辊套在使用过程中表面经常被磨损或损坏.在实际生产过程中经常采用焊接的方法修复连铸辊套,介绍了用CO2气体保护焊和埋弧自动焊修复连铸辊套的工艺心得.     

140万吨/年延迟焦化焦炭塔现场组焊安装的质量控制

分析了大型焦炭塔的结构特点,介绍了焦炭塔的现场组装焊接工艺及其焊接质量控制过程;为保证焊接质量,在筒体纵缝焊接采用了分段退焊工艺及在筒体横缝焊接采用了埋弧自动焊工艺,并制定了合理的焊接、无损检测、热处理质量控制工艺。实践证明,所采用的焊接工艺及所制定的质量控制措施是有效的,大型焦炭塔的制造是成功的。