高压下TIG电弧稳定性的研究

分析了影响高压焊接电弧稳定性的因素，建立了高压电弧稳定性破坏的故障树，对故障树进行了定性和定量分析。在此基础上，在自制的高压模拟试验装置中进行了不同压力下TIG电弧稳定性试验，试验表明，在环境压力为0．2MPa、0．4MPa和0．7MPa时，选用合理的焊接工艺参数，TIG电弧均能稳定燃烧。     

水下焊接技术及其在我国海洋工程中的应用

简述了水下焊接技术及其水下焊接的主要方法。针对国内“十五”期间研究开发的水下干式管道维修系统，介绍了实际应用于海洋工程中的水下干式高压焊接系统的关键技术及其技术集成，并探讨了水下焊接技术的发展趋势。     

水下湿法FCAW电弧稳定性的研究

水下焊接技术是海洋油气设施建造及核电站维修的关键技术之一。水下湿法电弧稳定性是水下湿法焊接的关键问题，提高水下焊接电弧稳定性对促进水下焊接技术具有重要意义。搭建了用高压舱模拟水下环境进行FCAW水下湿法焊接的试验平台，以焊接电流、电压和水深三个焊接工艺参数为自变量，设计了三因素五水平的响应曲面( RSM)试验方案，建立了电弧稳定性与焊接参数之间的响应曲面模型。对单一焊接参数以及参数间的交互作用对电弧稳定性的影响、水下湿法焊接电压电流的匹配规律和焊接工艺范围进行了研究。     

高压油管密封性试验装置改进

通过运用世界先进的柴油机高压共轨系统技术和压力控制原理,对试验装置进行了优化改造,最终解决了高压油管强度和密封性油压试验存在的问题,确保了产品质量。     

高压绝缘试验装置中的自动升压和系统

介绍高压绝缘试验装置的自动升压系统，着重论述升，降压的指数式过程，双迥路控制电路及尖刺电压的消除。     

系统耦合试验装置监控系统设计

本文介绍了监控系统设计,包括各个工艺系统的设计、报警连锁、控制室等的设计。系统耦合试验装置监控系统对整个系统进行监控,并得到发电元件和散热部件的试验数据,以及各分系统的运行状态。监控系统负责对系统耦合试验装置各个工艺系统进行数字化监控,是系统耦合试验装置的指挥中心。     

高压容器内壁(水下)应力测量试验

依据本文设计一套高压容器内壁应力测量系统来进行实验。针对高压容器的水下应变测量必须解决的问题作了阐述。经实验表明，该系统性能稳定、操作简单。     

淹没式喷嘴反推力测量及其系柱试验装置设计

喷水推进具有噪声低、空泡性能好、易于矢量调节等优点，已成为水下机器人（ROV）推进技术的研究热点。喷水推进依靠喷嘴将泵产生的压力能转化为高压水动能，产生的反推力是压力和黏性阻力作用在高压腔以及喷嘴上的综合效果，该反推力的大小是推进性能研究的重点。对几种不同形状和参数的喷嘴反推力进行仿真和试验对比。采用Fluent软件对喷嘴进行流场内部仿真，并且通过后处理文件计算出喷嘴的反推力大小。现有测量喷嘴反推力的相关试验装置与实际工况存在较大差异，根据螺旋桨系柱推力试验方法，提出并设计一种新的喷嘴反推力测试装置。该试验装置动力由岸基高压海水泵源供给，通过溢流阀调节喷嘴入口压力，喷嘴固定在ROV框架上，利用拉力传感器测量ROV框架在喷嘴射流驱动下的系柱拖力，进而得到喷嘴射流反推力与输入压力的关系。该试验装置为在水淹没条件下研究喷水推进系统提供了试验条件。     

高压垫片静密封性能试验装置研究

本文着重介绍高压垫片静密封性能试验装置的设计研制和有关测试技术、测试方法的试验研究。     

高压焊接阀门试压方法的探讨

高压焊接阀门试压方法的探讨镇海石化总厂机修厂张学军阀门在安装使用前必须经过强度和密封等试验，以确保合格的阀门用于生产装置，由此产生了阀门试压问题。对于高压大中口径焊接阀门，我们经过几年的实践改进，采用了如图所亏的试压设备，该设备采用液压传动，效果很好...     

Seam Tracking Technology for Hyperbaric Underwater Welding

Automatic weld seam tracking technology to be used in hyperbaric underwater damaged pipeline repair welding is much more important, because of poor bevel preparation and severe working condition. A weld seam tracking system based on digital signal processing(DSP) passive light weld image processing technology has been established. A convenient charge coupled device(CCD) camera system was used in the high pressure environment with the help of an aperture and focus altering mechanism to guarantee overall image visibility in the scope of pressure below 0.7 MPa. The system can be used in the hyperbaric environment to pick up the real welding image of both the welding arc and the welding pool. The newly developed DSP technology was adopted to achieve the goal of system real time characteristics. An effective weld groove edge recognition technique including narrow interesting window opening, middle value wave filtering, Sobel operator weld edge detecting and edge searching in a defined narrow area was proposed to remove the guide error and system accuracy was ensured. The results of tracking simulation and real tracking application with arc striking have proved the validity and the accuracy of the mentioned system and the image processing method.     

脉冲GMAW焊接极性对高压环境下焊缝成形的影响

高压环境会造成焊接电弧收缩,焊接过程较不稳定。鉴于脉冲熔化极气体保护焊(Pulsed gas metal arc welding,GMAW-P)具有热输入量可控、电弧挺度较好等特点,将其应用于高压环境下是一个有益尝试。开展压力在0.1~1.0 MPa范围内不同极性下的干法GMAW-P试验,分析随着环境压力升高电流电压波形图的变化趋势,由此确定焊接极性不同时焊接过程稳定性随环境压力升高的变化规律;在此基础上,对比分析不同极性下GMAW-P焊接飞溅及焊缝成形随压力升高的变化规律。随着环境压力增加,在直流反接情况下,电流电压波形周期性逐渐减弱,焊接过程趋于不稳定,飞溅逐渐增多,焊缝成形变差;而采用直流正接方式时,高压下电流电压波形的周期性虽然不及常压下稳定,但相较于同一压力下的直流反接方式,周期规律性有所增强,焊接过程相对稳定,且焊接时产生的飞溅比采用直流反接方式时的飞溅少且颗粒小。另外,随环境压力增加,两种极性GMAW-P焊缝宽度均有变窄的趋势,余高也随之增加。对高压环境下不同焊接极性GMAW-P的电弧形态及相应电弧力进行深入探讨,明确了上述现象出现的原因,为高压环境下焊接工艺的改进提供有效的理论依据。     

Welding polarity effects on weld spatters and bead geometry of hyperbaric dry GMAW

Welding polarity has influence on welding stability to some extent, but the specific relationship between welding polarity and weld quality has not been found, especially under the hyperbaric environment. Based on a hyperbaric dry welding experiment system, gas metal arc welding(GMAW) experiments with direct current electrode positive(DCEP) and direct current electrode negative(DCEN) operations are carried out under the ambient pressures of 0.1 MPa, 0.4 MPa, 0.7 MPa and 1.0 MPa to find the influence rule of different welding polarities on welding spatters and weld bead geometry. The effects of welding polarities on the weld bead geometry such as the reinforcement, the weld width and the penetration are discussed. The experimental results show that the welding spatters gradually grow in quantity and size for GMAW with DCEP, while GMAW with DCEN can produce fewer spatters comparatively with the increase of the ambient pressure. Compared with DCEP, the welding current and arc voltage waveforms for DCEN is more stable and the distribution of welding current probability density for DCEN is more concentrated under the hyperbaric environment. When the ambient pressure is increased from 0.1 MPa to 1.0 MPa, the effects of welding polarities on the reinforcement, the weld width and the penetration are as follows: an increase of 0.8 mm for the weld reinforcement is produced by GMAW with DCEN and 1.3 mm by GMAW with DCEP, a decrease of 7.2 mm for the weld width is produced by DCEN and 6.1 mm by DCEP; and an increase of 3.9 mm for the penetration is produced by DCEN and 1.9 mm by DCEP. The proposed research indicates that the desirable stability in the welding procedure can be achieved by GMAW with DCEN operation under the hyperbaric environment.     

5万m~3LNG储罐9%Ni钢的焊接和质量控制

结合5万m3LNG低温储罐的建造,对9%Ni钢的埋弧自动横焊和手工焊条电弧焊进行了大量的工艺试验,试验表明,采用ERNiCrMo-4焊丝、相应的焊剂和合适的焊接规范能得到性能合格的焊接接头,并能实现自动焊接。介绍了大型LNG储罐9%Ni钢底板和壁板安装制造的焊接工艺及焊接顺序,控制了内罐的焊接变形;并介绍了9%Ni钢焊接质量检验的过程和射线检验采取的有效措施,保证了5万m3LNG储罐的施工质量,为LNG储罐施工的焊接检验积累了经验,对LNG储罐的建造具有重要的实用价值。     

船用水泥罐充压管路智能化设计

船用水泥罐充压系统能使散装物料保持絮状流动,为准确计量物料提供方便条件。对船用散装水泥罐充压系统管路结构改进设计,将充压管路进行树状分布,通过远程传感器对气室内的压力分布情况进行实时监测和调整,使絮状物料始终保持均匀流动状态,提高水泥罐的计量精确性。     

高精度水下目标模拟与应答技术的研究

针对模拟水下目标的回波，研究了一种对大动态范围内的声纳信号进行增益控制及应答的方法。方法采用数字波形存贮技术，数字增益控制技术，对所接收的信号波形进行处理，并采用数字波形恢复技术恢复并转发该信号，具有波形模拟逼真、应答精度高等优点。本文论述了该方法的工作原理、系统硬件实现方案及水池实验的结果。     

管道连接件安装机器人液压系统管路精简设计

水下大口径管道沟槽式连接件安装作业机器人是有缆机器人,缆索中包含有液压管路和通讯线路。为了减小缆索对水下作业主体运动的影响,将电磁阀由控制柜移到水下作业主体上,使用水声通讯代替部分电缆通讯,并改进了相应的控制软件和硬件系统。该方法可以有效精简液压系统管路,减小缆索直径,降低缆索对水下作业主体运动的影响,同时也降低了母船上绞车的复杂程度。     

铝合金贮箱法兰件自动化焊接工艺研究

对2219铝合金开展对接法兰的自动化焊接研究,在优化装配过盈量及焊接工艺的基础上,通过拉伸试验机、光学显微镜、扫描电镜对接头力学性能及微观组织进行分析研究。结果表明,对于典型厚度5 mm和8 mm的法兰件,通过单面两层自动焊接工艺优化后,其抗拉强度及塑性指标远大于贮箱制造要求,且低温下优于常温,可以满足产品需要。     

球形储罐焊接角变形的控制

在分析球形储罐焊接角变形产生原因的基础上,从焊接坡口形式、刚性固定方法和焊接顺序等方面探讨了减小和控制焊接角变形的工艺措施。     

New approach to maintaining liquid flow rate stability in national primary standard

New approach to maintaining liquid flow rate stability in primary standard calibration facility is proposed. It takes advantage of primary standards with constant static head and does not require high-altitude installation of the pressure tank. To implement the proposed approach, the pressure tank is installed in the water pipeline of the Standard between the pumping station and the measurement pipeline. Pressure in the air cushion above the liquid in this tank is maintained automatically, as well as the liquid level in the pressure tank. It has been demonstrated that in order to stabilize the flow, it is sufficient to employ the controlling impacts in the form of air supply/withdrawal and adjustment of variable-frequency drives of pumps. The air is supplied and withdrawn from the air cushion by a set of critical flow nozzles, which are activated depending on the absolute pressure of air in the cushion. The liquid level in the tank is controlled by adjustment of variable-frequency drives of pumps based on the information on the hydrostatic head (liquid level) in the tank. Experimental study of the flow stabilization system of the National Primary Standard GET 63–2017 for mass and volume of liquid, mass and volumetric flow rates of liquid (Kazan, Russia) confirmed high efficiency of the proposed approach.