全焊接金属密封热交换器的疲劳特征探索

运用分析软件对全焊接金属密封热交换器进行了疲劳特性分析,通过特殊的分析思路,验证了此种设备在相应压力循环下是否疲劳,以及最易疲劳的位置处于设备的何处。

大型球罐高效脉冲MAG全位置自动焊接系统

球罐脉冲MAG全位置自动焊具有绿色环保、高效节能等优点,与焊条电弧焊相比,其焊接工艺参数可控,焊接变形量小,更有利于保证球罐的焊接质量,但需解决曲面爬行轨道、焊接小车、机头摆动机构、控制系统、配套的金属粉型焊丝及焊接工艺等诸多技术难题。针对量大面广的Q370R钢制大型球罐,通过对球罐脉冲MAG全位置自动焊接系统中多项子系统的攻关试验研究,实现了自动焊焊接装备在球罐上全方位平稳运行,且价格低廉,研制的金属粉芯焊丝质量稳定,适于Q370R钢制球罐全位置焊接,焊缝金属力学性能较佳,球罐自动焊焊缝成形美观,完全替代了原始的焊条电弧焊,应用前景广阔。

姿轨控系统高压气路全焊接结构可行性研究

为了实现液体姿轨控动力系统的长期贮存,针对高压气路全焊接结构开展了可行性研究。分析了高压气路系统全焊接结构形式所需异种金属焊接、全位置焊接、总装装配工艺等相关技术进行,并通过各类样件的试制验证了实现高压气路全焊接结构的可行性。

Study on the all position automatic pipeline backing weld machine

As a result of the lower backing weld efficiency, the applying of automatic welding is seriously limited. So a kind of special automatic welder is designed and manufactured for backing weld. This paper introduces the character of the assembled pulse CO2 arc welding machine which has strong penetrability. It specifies the technology of controlling the parameters of all position automatic welding by computer and multi-axis controller. Moreover typical welding procedure parameters are provided. It is proved by examination that the economical and practical equipment and technology are suitable for the long-distance transmission pipeline, and it has a good foreground of spreading and applying.

不锈钢管道全位置熔化极气保自动焊技术

为了提高厚壁不锈钢管道焊接质量及焊接效率、降低施工成本,实现管道全位置焊接,开发一种全位置熔化极气保自动焊技术。焊接系统由智能控制电源、楔形柔性摩擦轨道、控制系统等组成。开展焊接工艺试验,对焊接接头进行拉伸力学性能测试、弯曲性能测试、晶间耐腐蚀性能试验、化学成分分析、微观金相分析以及对焊缝进行了铁素体含量检测等一系列试验,结果表明,各项性能指标均能符合压力管道施工标准要求。工程应用中焊接合格率达到96%以上,各项指标达到设计要求,焊缝质量可靠,降低了施工成本,实现了厚壁不锈钢管道全位置自动焊接。

金属粉芯焊丝+RMD技术在管道全位置根焊中的研究及应用

金属粉芯焊丝是药芯焊丝和实芯焊丝的混合物,具有熔敷速度较高、易于调节合金成分、狭小的根焊方便、焊接飞溅量少、熔渣量少等特点;RMD技术是由软件控制的,对短路过渡作出精确控制的一种技术。针对国内长输管道全位置根焊施工焊接技术现状,选用金属粉芯焊丝+RMD技术,制定焊接工艺方案,进行焊接工艺试验,成功实现了管道全位置根部半自动焊接。试验结果表明,焊接过程熔池稳定,易在根部产生高质量熔深,焊逢两侧熔合良好,可形成高质量的焊缝。

海上风电结构焊接用金属粉芯焊丝的研制和应用

针对海上风电项目采用船用E级板的焊接工艺要求,通过对金属粉芯焊丝的合金成份和力学性能的设计,以及通过对焊丝的抗气孔性、低温韧性、低烟尘和低飞溅性、电弧的穿透性及全位置焊接性等方面的优化设计,研制出了一款适合于半自动焊用的金属粉芯焊丝.通过焊接工艺评定试验证明,该种焊丝的低温冲击性能满足海上风电项目的建造要求,满足全位置单面焊双面成型的要求,并成功用于海上风电项目的建造,焊接效率和焊接质量可大幅提高.

Corrosion Study of Base Material and Welds of a Ni-Cr-Mo-W Alloy

Alloys containing chromium （Cr） and molybdenum （Mo）, as the major alloying elements, are widely used in various industries where the material experiences corrosive environments. Chromium （Cr）, when added in an optimum amount, forms a Cr203 passive film which protects the underlying metal in aggressive solutions. Molybdenum （Mo） forms its oxides in the low pH solutions, thus, enhances the uniform corrosion resistance of an alloy in reducing acids and assists in inhibition to localized corrosion. Minor alloying elements, like tungsten （W） and copper （Cu）, also improve the overall corrosion resistance of an alloy in specific solutions. In the present study, corrosion resistance behavior of commercial iron- based alloys （316L SS, 254 SMO and 20Cb3） and nickel-based alloys （Mone1400, Alloy 625 and C-276） was studied in the acidic solutions. While the corrosion behavior of wrought alloys has been widely studied, there is little to no information on the corrosion performance of their welds, typically being the weak regions for corrosion initiation and propagation. Therefore, an attempt was undertaken to investigate the uniform and localized corrosion performance of base metal, simulated heat-affected zone and all-weld-metal samples of a Ni-Cr-Mo-W alloy, C-276. The study was conducted in aggressive acidic solutions. Various corrosion and surface analytical techniques were utilized to analyze the results.

X70钢管道全位置激光-MAG电弧复合根焊焊缝成形试验研究

针对X70钢管道全位置激光一熔化极活性气体保护（MAG）电弧复合根焊焊接过程中，管道焊接3-6点位焊缝背面易出现内凹，开展了管道全位置激光一MAG电弧复合根焊焊缝成形试验研究。试验结果表明，激光一电弧复合焊接能量输入、焊枪角度对焊缝背面内凹影响较大；焊缝背面内凹可能是由于熔池液态金属重力作用导致焊缝熔融金属下淌所致。通过变参数能量输入方法，从3点位到6点位逐渐降低激光一电弧复合焊接功率；并向上倾斜焊枪角度使激光和焊缝切线方向成80。时，可利用保护气吹力和电弧力“托住”熔池，有效抑制内凹缺陷，改善焊缝成形。此外，发现焊缝背面有无内凹对静载拉伸性能基本无影响，有内凹管道的抗拉强度可达到596MPa以上，但焊缝背面内凹大幅降低了管道疲劳性能。