15CrMoR钢药芯焊丝气体保护焊工艺及接头组织性能

通过15CrMoR钢的药芯焊丝气体保护焊焊接试验,研究15CrMoR钢药芯焊丝气体保护焊的焊接工艺和接头的组织性能,结果表明:药芯焊丝气体保护焊的工艺性能良好,焊接接头中焊缝和热影响区的微观组织为贝氏体和铁素体,焊接接头的拉伸、侧弯和冲击等力学性能均满足15CrMoR钢母材的要求,确定15CrMoR钢采用药芯焊丝气体保护焊工艺的可行性。     

15CrMoR钢碱性渣系药芯焊丝焊接工艺及接头性能的研究

采用CO2气体保护药芯焊丝电弧焊,研究了15CrMoR钢碱性渣系药芯焊丝的焊接工艺性,及焊接接头的组织和性能.结果 表明,焊接过程中飞溅较大,焊后焊缝成形良好,焊接接头中焊缝和热影响区的微观组织为贝氏体,与酸性渣系药芯焊丝的焊接接头相比冲击吸收能量有明显提高,各项性能满足母材要求.     

核电用奥氏体不锈钢机械焊焊接工艺研究

本文对核电用奥氏体不锈钢板采用不同机械焊工艺获得的焊接接头进行分析,包括焊接接头的强度、塑性、韧性、高温强度、抗腐蚀性能及微观组织等,结果表明,在合理的焊接工艺下,采用合理的药芯焊丝气体保护焊和埋弧焊焊接工艺均会获得具有良好性能的焊接接头,为奥氏体不锈钢机械焊在核电压力容器中的生产应用积累了试验数据。     

气保药芯焊丝用于低温钢压力容器制造的性能研究

焊接是石油化工低温钢压力容器制造的重要工序,随着石油化工装置规模不断扩大,对低温钢压力容器的焊接质量和焊接效率提出了越来越高的要求。气保药芯焊接材料因其高质量、高效率、易于同母材匹配等优点而应用广泛,但在低温钢压力容器制造领域还应用较少。以典型的HOBART XL550气保药芯焊丝为例,根据低温钢压力容器制造的焊接要求,进行了熔敷金属扩散氢检测试验、焊丝吸潮性试验、热处理性能测试、CTOD测试。测试结果表明:XL550气保药芯焊丝最高扩散氢含量均小于4m L/100g熔敷金属,满足低氢焊接要求;焊态和热处理状态下的强度、硬度和冲击韧性也均满足压力容器的焊接要求;具有良好的止裂性能。在性能测试的基础上进行的现场对接焊试验结果表明,XL550气保药芯焊丝满足低温钢压力容器低氢焊接和热处理前后机械性能稳定的要求。     

药芯焊丝气体保护焊在锅炉受压焊缝中应用的工艺研究

通过试验研究，选择适当的焊接材料、焊接工艺参数，克服了药芯焊丝气体保护焊易出现的缺陷，用以替代以往锅炉碳钢集箱受压焊缝生产中手工焊的传统焊接方法，将该焊接方法应用于锅炉碳钢集箱受压焊缝的生产中，提高工作效率3-5倍，降低了生产成本。     

空冷换热器换热管-管板焊接方法及应用简介

本文介绍了空冷换热器换热管-管板的焊接方法。可采用焊条电弧焊、实芯或药芯焊丝的熔化极气体保护焊、手工钨极氩弧焊、自动化焊接等方法进行焊接。     

药芯焊丝电弧焊在受压件焊接中的应用试验

本文对两种碳钢药芯焊丝进行焊接工艺性试验,焊接工艺评定试验,系统地研究了药芯焊丝电弧焊的焊接工艺,找出了最佳的焊接规范,为药芯焊丝电弧焊推广应用于锅炉受压元件焊接作了技术准备。从而优化了焊接工艺,提高产品质量,为取代传统手工电弧焊作了可行性分析。     

大口径接管和法兰内壁不锈钢气体保护自动堆焊设备及工艺

本文介绍了渭河３０万吨／年合成氨化肥工程不锈钢复合板容器中大口径碳锰钢及铬钼铜接管和法兰内壁超低碳不锈钢药芯焊丝Ａｒ＋ＣＯ２混合气体保护自动堆焊方法，堆焊设备、堆焊材料、堆焊工艺及其影响因素和工艺措施及所获得的良好堆焊接和堆焊接效果。     

集箱短管接头角焊缝埋弧焊工艺试验研究

为提高锅炉集箱短管角接接头焊接机械化程度及角焊缝质量,上海锅炉厂有限公司创新性地采用"内孔氩弧焊+埋弧焊"工艺方法,并与合作方联合开发"集箱短管接头角焊缝埋弧焊设备"。通过对高端材料、几种规格和不同坡口型式的短管接头进行的大量焊接试验,最终确定了最佳的坡口型式及焊接工艺规范参数,且获得了焊缝表面成型美观、接头质量可靠等性质优良的焊接接头,生产效率大大提升,为工厂生产应用和大面积推广打下了基础。     

CO_2气体保护焊在560吨加氢裂化反应器制造中的应用

石油化工用单件重量为560吨的加氢裂化反应器，简体、封头和接管内壁及接管端面、法兰密封面均需堆焊不锈钢耐蚀层，采用管状药芯焊丝和CO2气体保护焊与手工焊相结合的方法。文中介绍产品结构概况、焊接工艺评定、产品施爆情况和结论，图1表4。     

12Cr2MoWVTiB蛇形管的焊接技术

在深入分析了12Cr2MoWVTiB钢的成分特点以及其焊接性的基础上,以锅炉蛇形管12Cr2MoWVTiB钢为研究对象进行了焊接工艺试验,试验结果表明:采用手工钨极氩弧焊,选择直径为2.5 mm的H10Cr2MnMoWVTiB焊丝作为焊接材料,并且焊接时采用直流正接的方式,采用经试验确定的合理工艺参数焊接后得到了质量合格的焊接接头。     

Welding of multilayer pipes in the manufacture and construction of high pressure gas pipelines

The technology of welding large diameter multilayer pipes in shop production is described. Circumferential and lap welding of such pipes to eliminate pore and other defect formations are considered in detail, with data on welding processes, conditions and materials. Experience in the construction of multilayer high pressure gas pipeline sections is described.     

A novel liquid-shielded welding solution for diffusible hydrogen content restriction and metal transfer controlling in underwater FCAW condition

Hydrogen produced by water decomposition caused high diffusible hydrogen content in deposited metal, but also produced numerous spatter and unstable fragments which were considered as the main reason that deteriorated the weld formation during underwater wet flux cored welding (FCAW). Drawn inspiration from onshore gas shielded welding, in this paper, a liquid shielded welding method was invented. As a by-product of biodiesel, glycerol was chosen as liquid protectant. The results suggested that the diffusible hydrogen content in deposited metal was reduced by 62.4% with glycerol shielded due to its higher decomposition threshold and less hydrogen in decomposition products. Arc bubbles were attached to the molten pool surface and their expansion rate and rising velocity were slowed down resulted in more stable droplet transfer process and less spatter owing to high viscosity glycerol protectant. Almost porosity-free joints were obtained and the mechanical properties of the welded joints were also improved.     

浅谈CO2气体保护焊接中的几个问题

气体保护焊凭借其焊接时能量集中、试件变形小、焊接效率高、焊缝韧性好、操作简单,且焊接速度快、不需清渣、换焊条等特点,成为当代一种高效节能的焊接方式。     

Determination of equilibrium wire-feed-speeds for stable gas metal arc welding

In gas metal arc welding (GMAW), a consumable electrode wire is fed normally at a pre-determined constant speed in order to achieve a stable welding process for given welding conditions. In this article, a comprehensive mathematical model for GMAW was employed to study the interplay among electrode melting; the formation, detachment, and transfer of droplets; and the plasma arc under various welding conditions. It is found that a stable GMAW process can be obtained through a balance between the wire-feed-speed (WFS) and the dynamic electrode melting rate due to the transient behavior of plasma arc. Otherwise, an unstable welding process including electrode burned-back or stick-onto the weld pool could occur. The model-predicted equilibrium WFS varying with welding current and feeding-wire diameter is in good agreement with the published empirical results obtained through a trial-and-error procedure.     

Automatic welding of pipeline in Japan: Part 1—Some experiences with site applications

Recent experiments on automatic welding of pipeline in Japan have been based on the short-arc welding process and aimed at reducing the welding time by $\text{v}\text{?}$arying the welding conditions and by effecting improvements to the welding equipment.The short-arc process has been employed increasingly in the actual pipeline installation work, exhibiting a number of advantages such as stabilisation of both the quality of weld and the welding time. However, it has presented various problems, including the difficulty in jointing one elbow with another or with a cut pipe and the applicability to a narrow work site.For automatic welding of large diameter pipes for water and town gas supply, on the other hand, the electro gas process has enjoyed a broadened expanse of application by virtue of its high productivity.Further, the pulsed TIG process by programmed control was applied experimentally and produced successful results in the laying of pipe type cable pipeline.     

Fabrication of high aspect ratio ceramic micro-channel in diamond wire sawing as catalyst support used in micro-reactor for hydrogen production

Ceramic is an ideal material for preparing micro-channel catalyst supports with their characteristics of high temperature resistance, corrosion resistance and mechanical strength. High aspect ratio micro-channel structure has the advantages of large specific surface area, strong mass and heat transfer performance and high material utilization. However, ceramic materials are hard and brittle, and it is difficult to fabricate micro-channel structures with aspect ratio more than 1.5:1 by traditional processing methods. In this paper, a cutting method of large diameter diamond wire sawing was proposed. The micro-channels with width of 520 μm and aspect ratio of more than 4:1 was successfully fabricated by this method. Furthermore, the integrity of the micro-channel structure processed by diamond wire sawing was analyzed. And than the effect of surface morphology in different processing parameters on the catalyst loading performance were studied. The catalyst loading strength of ceramic slices with different surface morphology was tested. Finally, the ceramic micro-channel array was used as the catalyst support in micro-reactor for hydrogen production via methanol steam reforming (MSR). The methanol conversion rate and H₂ production rate could reach 87.8% and 74.6 mmol/h, respectively under GHSV 12600 ml/g·h at 300 °C. The experimental results show that the large-diameter diamond wire sawing technology can be used to process ceramic microchannels with high aspect ratio; using ceramic microchannel arrays as catalyst supports in hydrogen production can obtain better reaction performance; the feasibility of ceramic materials were broadened as microchannel catalyst supports.     

核电管系的焊接自动化研究

核电再热管及辅助管系为公司重要生产部件,焊接量大,形状复杂,现多采用手工氩弧焊打底、半自动气保焊填充方法焊接,生产效率低、焊接质量不高。文章通过对产品结构分析,提出各自适合于再热管及辅助管系适合的自动焊方法,逐步实施,效果显著。     

高温合金叶片修复技术的应用与发展

高温合金因具有良好的耐腐蚀性、抗氧化性、蠕变强度等性能,在航空及电力设备制造行业中有着重要的作用．常用于制造燃气轮机叶片等复杂构件。目前燃气轮机叶片多采用铸造成型,铸造过程中不可避免的会产生缺陷．且叶片在服役过程中因为高温高压蒸汽的腐蚀和冲刷．也会产生损伤。文章综述了镍基合金叶片修复技术的研究进展,重点介绍了国内外一些先进的叶片修复方法,深入分析了不同修复方法的特点,并对燃气轮机叶片修复技术的发展前景进行了展望。