高效舵的焊接工艺评定试验

介绍了瓦锡兰设计的高效舵铸钢件550W和E36钢板焊的焊接结构焊接工艺评定试验(WPQT)的结果并对高效舵的焊接制造提出指导性意见.     

华铸CAE软件在大型挂舵臂铸钢件生产中的应用

设计了大型原油船挂舵臂铸钢件初始工艺,并且利用三维绘图软件Solidworks对该工艺进行了三维造型,得到了与华铸CAE软件接口的STL文件,应用该软件进行了温度场的凝固模拟,预测了缩孔、缩松缺陷产生的部位.在此基础上对其铸造工艺进行了优化.结果表明,合理配置冒口、冷铁、浇注系统等.可以保证铸件顺序凝固,生产出符合要求的挂舵臂铸钢件.     

大型船舶挂舵臂充型与传热耦合的计算机模拟及优化

根据铸造工艺设计人员的经验,设计了大型船舶挂舵臂铸钢件初始工艺,应用华铸CAE软件对其进行了充型与传热耦合的数值模拟。在此基础上对其铸造工艺进行了工艺优化。结果表明:合理配置冒口、冷铁、阶梯式浇注系统等,可以保证铸件符合顺序凝固,生产出符合船级社标准的挂舵臂铸钢件。     

大型凹箱形梁结构件的焊接变形控制

针对大型凹箱形梁的结构特点及焊后变形情况,合理设计坡口形式,制定切实可行的装配焊接工艺,采用CO_2焊及手工电弧焊相结合的方法成功地控制了焊接变形,构件焊接质量满足设计要求。     

切割带钝边的管道焊接坡口的数学模型及仿真

针对三通接头焊接的焊前坡口切割问题,对斜边焊接坡口和带钝边焊接坡口进行对比,分析了带钝边焊接坡口的优点,阐述了管件带钝边焊接坡口支管切割及主管切割原理;在现有斜边焊接坡口切割数学模型的基础上,分别建立了带钝边焊接坡口支管切割及主管切割数学模型.用AutoCAD VBA工具对切割数学模型进行仿真分析,验证了所建立的数学模型的可靠性和实用性.为三通接头焊接的焊前坡口切割提供了新的理论依据与思路.     

ZG45钢越南桥散索鞍的埋弧焊工艺

针对45钢越南桥散索鞍的焊接,在工艺分析的基础上,制定了合理的焊接工艺并得以实施.结果表明:采用CO2焊打底和埋弧焊填充盖面相结合,选择正确的焊接参数、坡口形式和相应的焊前、焊中及焊后热处理等工艺,能够完全满足结构的设计要求.     

国内最大挂舵臂在鞍钢铸造成功

正2017年2月,由鞍钢集团铸钢公司生产的超大异型铸件挂舵臂完成浇注和热处理工作,经打磨加工后将发往客户。该铸件为目前国内最大挂舵臂,它的成功生产标志着鞍钢铸造技术水平实现了新的提升,使铸造船用铸钢件成为鞍钢新的经济增长点。挂舵臂是一种支承半悬挂船舵的臂状构件,为远洋货轮吊挂舵结构的关键件。该铸件对钢水质量有着严格要求,同时,因其造型复杂、所有剖面均为曲面、铸造难度很大。     

长输油气管道焊接材料设计用量计算

由于目前油气长输管道常用的焊接方法有焊条电弧焊、药芯焊丝半自动焊和实心焊丝气体保护自动焊,故针对不同焊接方法及不同焊接坡口形式,制定并详细介绍了焊接材料设计用量计算方法,满足了精细化设计的要求。     

盾构机焊接/切割机器人的研制

针对盾构机盾体结构复杂、焊接耗时长这一问题,设计了全自动焊接/切割机器人.该机器人同时具备焊接/切割功能,能够进行多层多道自动焊接,并满足焊缝自动切割要求;焊接机器人控制系统具有横焊、平焊、立焊三种位置的焊接数据库,每个数据库中层数、道数可灵活设置;具有坡口规划和轨迹存储功能,实现不规则坡口的多层多道自动焊.利用所研发的焊接/切割机器人进行盾体自动焊接及切割试验,试验结果表明,该机器人能够满足盾构机盾体焊缝自动焊接及切割要求.     

大型挂舵臂铸钢件冶炼及热处理工艺

分析了挂舵臂铸钢件常见的组织缺陷及产生原因,提出了铸钢件的冶炼及热处理工艺。结果表明:严格控制挂舵臂化学成分、冶炼工艺和热处理工艺,可消除缩松、裂纹等缺陷,在钢中加入微量的稀土元素,能够细化晶粒,同时改善组织中夹杂物的形态和分布,使钢的塑性和韧性显著提高。     

复合容器的焊接

针对容器内表面全部实施合金625的堆焊覆层技术条件要求,对于合金625的堆焊覆层,从堆焊覆层工作表面以下2 mm处的铁元素含量应不超过5%,接管法兰与筒体和管帽的部件热处理应在堆焊覆层后和不锈钢内件焊接前进行,筒体与管帽的闭合焊缝焊接和热处理存在问题,采用坡口预边堆焊隔离层,部件焊后热处理后冷态焊接闭合焊缝,图纸要求内壁堆焊层厚度和坡口隔离层厚度不小于3 mm,经焊接实验证明其复合容器堆焊覆层最小厚度应为5 mm,用焊接工艺评定验证了该结构的各项性能指标均满足标准和规范要求。     

基于单片机控制的Q890D钢/6061铝合金MIG焊接头组织与性能

选取TI公司开发的MSP430F149单片机为控制核心的MIG焊过程控制系统,研究焊接电流、焊接速度、焊接方向&焊枪角度和钢侧坡口角度等对Q890D钢/6061铝合金焊缝成形的影响,并在优化焊接工艺下分析焊接电流和焊接速度对Q890D钢/6061铝合金MIG焊接头界面区组织和接头力学性能的影响。结果表明:Q890D钢/6061铝合金适宜焊接方向为右焊法,适宜的焊枪角度为10°,适宜的钢侧坡口角度为45°,焊丝位置宜处于钢侧坡口中部,适宜的焊接电流和焊接速度分别为105 A和50 cm/min;不同焊接电流和焊接速度的Q890D钢/6061铝合金MIG焊接头的断裂位置都处于界面区,而MIG焊过程中界面区形成的靠近钢侧的(Fe,Cu)2Al5和靠近铝侧的(Fe,Cu)4Al13相的双层金属间化合物层结构有助于改善焊接质量。     

大型出口远洋货轮挂舵臂的铸造

大型出口远洋货轮挂舵臂铸钢件重量大,形状复杂,内部质量要求高,生产难度大。以生产实践为基础,论述了大型船舶挂舵臂铸件(150 t)生产过程中易产生的缺陷和防止措施。结果表明,采用合理的型砂和分层造型方法,严格控制熔炼工艺,采用优化浇冒口系统,可消除铸件内部缩孔、缩松缺陷,避免铸件表面出现粘砂、砂眼,保证铸件的流线型外形,成功生产出符合商检和船级社要求的合格铸件。     

W型铸铝水冷机座压铸新工艺

本文介绍了一种环保能源牵引电机及发电机定子机座的制造方法。通过压铸模具的设计,在内筒体上铸出W型水道和W型阴槽及焊缝保护法兰;在外筒体上铸出W型阳槽,内外筒体压力铸造;然后在压力状态下通过W型导向,对内外筒体进行预热压装;最后内外筒体进行组焊制成电机定子水冷机座。本工艺结构巧妙,工序简单,防漏水、窜水,结构可靠。     

A microstructural and low-cycle fatigue investigation of weld-repaired heat-resistant cast steels

The multi-pass weld-repair of heat-resistant cast steels is carried out using an automated shielded metal arc welding (SMAW) process, with various filler materials and pre-heating at 400 °C. Specimens weld-repaired with a filler material more resistant than the heat-resistant cast steel (over-matching) generally crack within the base metal following the tenth filling pass, whereas specimens buttered with a soft alloy prior to welding remain free of cracks.The high temperature strain-controlled fatigue lifetime of material weld-repaired without buttering is lower than that of bulk initial material. This is due to an increase of the stress amplitude as a result of the so-called over-matching. In the case of material welded following a prior buttering, the fatigue lifetime is reduced because of the stress tri-axiality generated in the thin soft layer which prevents its plastic flow. As a consequence, it is concluded that even though buttering prevents cracking efficiently during welding, it is not acceptable as far as fatigue performance, especially lifetime, is concerned.     

Evaluation of high-strength steel castings possessing improved weldability

Naval components fabricated from HY-80 high-strength steels require an expensive preheat during welding to avoid heat-affected zone (HAZ) cracking. Quenched-and-tempered low-C, high-Ni steels were evaluated as potential alternatives to HY-80 steel castings with section sizes of 230 to 300 mm thickness. The investigation examined the feasibility of obtaining mechanical properties equivalent to HY-80 by heat treatment and evaluated weldability. The steel resulted in a crack-free casting, and preliminary tests suggest that it could be welded without preheating. Optimized heat treatment provided reasonably good yield strength (517 to 538 MPa) and Charpy impact toughness (63 to 80 J Charpy V-notch (CVN) energy at −73 °C). The former properties were just below HY-80 casting requirements of 550 MPa. Thus, while this composition might not be a suitable replacement for HY-80, there are other potential casting applications. These include surface ship shaft struts and rudder inserts that have less stringent strength and toughness requirements.     

30万t级矿砂船铸钢件挂舵臂的开发和铸造

毛重170多t的30万t级矿砂船用挂舵臂铸钢件是目前我公司生产的重量最大的船用件,其结构极为复杂,体积庞大,探伤等级要求极高,生产过程具有相当大的难度。结合本公司的实际情况,针对制造过程中容易出现的问题和铸造缺陷,制定了相应的铸造工艺,一次性成功地铸造出了符合客户和船级社要求的产品。     

Effect of PTA Hardfaced Interlayer Thickness on Ballistic Performance of Shielded Metal Arc Welded Armor Steel Welds

Ballistic performance of armor steel welds is very poor due to the usage of low strength and low hardness austenitic stainless steel fillers, which are traditionally used to avoid hydrogen induced cracking. In the present investigation, an attempt has been made to study the effect of plasma transferred arc hardfaced interlayer thickness on ballistic performance of shielded metal arc welded armor steel weldments. The usefulness of austenitic stainless steel buttering layer on the armor grade quenched and tempered steel base metal was also considered in this study. Joints were fabricated using three different thickness (4, 5.5, and 7 mm) hardfaced middle layer by plasma transferred arc hardfacing process between the top and bottom layers of austenitic stainless steel using shielded metal arc welding process. Sandwiched joint, in addition with the buttering layer served the dual purpose of weld integrity and ballistic immunity due to the high hardness of hardfacing alloy and the energy absorbing capacity of soft backing weld deposits. This paper will provide some insight into the usefulness of austenitic stainless steel buttering layer on the weld integrity and plasma transferred arc hardfacing layer on ballistic performance enhancement of armor steel welds.     

复合渗铝钢管的焊接工艺

通过焊接接头的力学性能试验、金相组织分析以及工程实践证明，采用普通不锈钢E309MoL焊条焊接20渗铝钢管道，只要采用正确的坡口加工方法和合理的焊接工艺，即可获得具有抗高温氧化和耐H2S等介质腐蚀的焊接接头。