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外文资料翻译
HISTORY OF UNDERWATER
WELDING TECHNOLOGY
Underwater welding technology is the development of the marine, offshore oil exploitation as well as assembly, maintenance such as oil platforms, pipelines and submarine positions in large marine structures such as one of the key technologies, but also ships emergency repair, salvage, construction of bridges and other necessary technically work means. Nuclear power development is the trend of the world in nuclear power plants within the reactor pressure vessel (RPV) for long-term work in the water, susceptible to stress corrosion cracking of the damage, structural repair of nuclear power, will face many challenges. To often use radiation-related underwater welding method, in order to reduce the working staff. Classification of underwater welding underwater welding generally divided into three categories: wet, dry, and local dry. And the dry can be divided into high-pressure dry underwater welding and common-pressure underwater welding pressure. Local laws, including drainage cover dry type, high-pressure curtain-style, steel brush, mobile air box and plasma arc MIG local dry method. Welding method used generally coated electrode welding, GTAW, GMWA, and FCAW. In addition to welding underwater welding in addition there is an explosion welding and FSW (friction stitch welding friction stitch welding), these two methods are all connected by solid phase technology. Following the development of underwater welding course:
1 Underwater wet welding technology
In 1802, a scholar named Humphrey pointed out that a continuous arc can burn under water, that pointed out the possibility of underwater welding, but its practical application is more than 100 years later, can not move the structure on land welding was done under the circumstances. In 1917, the British naval dockyard welders using underwater welding methods to block in the underwater part of ship rivets leaking cracks, this is the first application of underwater welding. The first published an article about underwater welding research papers in 1933, was jointly by Hibshrman Jensen and complete. 1932, Khrenov invented the thick skin of underwater medicine special electrode, the electrode surface top coat with waterproof layer, so that the stability of underwater welding arc has been improved to some extent. To the Second World War, underwater welding technology has been in the salvage boat, etc. play an important role. In 1971, Humble Oil Company of the Gulf of Mexico drilling platforms, underwater welding repair work is the first underwater welding technology used in offshore oil projects. 1985 produced the first batch of accredited diving welder, and developed a depth of less than 100m underwater wet welding. In 1987, underwater wet welding stainless steel piping in nuclear power plant has been applied to the repair work. 90's of last century, with the required repair of underwater engineering structures and the increase in the cost of increased repair dock, wet welding technology has been further developed. The development of underwater welding underwater wet welding plays an important role in the application. British Hydroweld a variety of underwater welding company achieved good practical results. U.S. Patent electrode -7018 `s drug electrode layer of aluminum skin, underwater welding can produce large amounts of gas, to avoid the erosion of the weld metal. University of Hanover, Germany-based slag - gas combined protection of the metal transfer process and protective mechanism developed from the protection of double-cored electrodes. Underwater wet welding is usually the water depth of less than 100 m, the direction of current efforts is to achieve 200 m water depth of wet welding technology breakthrough. Early 50s of last century, underwater wet welding arc welding had been applied in our country. 60's of last century China began developing its own dedicated underwater welding. South China University of Technology developed underwater welding rod available in 30 m water depth less than a good welding performance.
2 Underwater dry welding technology
● High dry underwater welding technology
High-pressure dry underwater welding, the idea is first proposed in 1954 the United States, officially for the 1966 production, mainly used for submarine pipeline repair. The maximum current is about 300 m water depth in the. The welding method, the bottom chamber is open, and through the work of deep water into the air pressure slightly larger than the pressure of the gas, the indoor air discharge water from the bottom of the openings, welding gas chamber in the dry conducted. MIG welding or commonly used, is the underwater welded TIG welding quality, basically, one of the best ways to weld level can land. In the 1970s, no high pressure welding of equipment developed. Germany, Norway, the United States, Britain began in the late 90's no such research and the establishment of high-pressure welding research center. From the mid 80s of last century, a number of research centers began to study 300 ~ 500 m water depth GTAW automatic welding systems and processes, or to test 500 ~ 1000 m water depth replacement of the adaptability of the welding technology. Now France, Germany, Norway, the United States, JEM hyperbaric welding research center operating pressure can reach the equivalent of 1000 m water depth. 90 years from the last century, the operating oil companies have begun to enter the deeper waters. The first water depth in this company should be operating under the Brazilian oil company (that is, the Brazilian national oil company), its operations in the Amazon basin, and depth to 1000 m. In China, along with the development of offshore oil industry, the urgent need to develop with independent intellectual property rights of high-pressure welding technology and dry. In the 2002 "863" program in there on the high-pressure dry underwater welding technology research projects. By the China Offshore Oil Engineering Corporation, Beijing Institute of Petrochemical Technology, Petroleum University, Shanghai Jiaotong University, Harbin Engineering University, the largest joint R&D Welding depth of 60 m. At present, the basic of the project has completed, the upcoming is sea trials.
● Dry underwater welding technology at atmospheric pressure
Dry underwater welding pressure welding quality although better, but its limitations more, especially with the increase of water depth, increasing air pressure around the arc, easy to destroy the stability of arc welding defect arising. Achieved in the absence of fully automated welding cases, the auxiliary diving welder operation, if the water depth exceeds the limit or dive diving high costs can not be implemented. In the technical level is unable to solve these problems, in order to overcome the deficiency of underwater dry welding, 1977, create underwater atmospheric dry welding equipment. In 1977, France LPS company first used this approach in the North Sea water depth 150 m Department successfully welded 426 mm diameter submarine pipeline. China has not yet dry underwater welding equipment at atmospheric pressure.
3 Local dry underwater welding technology
Local dry underwater welding technology .There are many ways. The late 70s of last century, Harbin Welding Institute maritime salvage bureau in Shanghai and Tianjin Petroleum Exploration Bureau, with the assistance of local drainage developed underwater CO2 gas shielded welding technology, referred to as LD-CO2 welding, is the local dry-type drain cover method, this method can be used to complete construction of a number of underwater tasks. High-pressure wet pad is applied by the Japanese a way to overcome some shortcomings of curtain-style, in turn the development of the Japanese steel brush. Mobile gas box in 1968, by the first put forward by British and American multinational company after applied to production. France has recently studied a rotary bell-type local dry underwater welding technology. In addition, plasma arc MIG local dry underwater welding is a promising local dry welding technology.
4 Solid-phase connection of underwater technology
● Explosive Welding
In the late 1970s, located within the blessing of Britain, underwater pipeline engineering company has successfully developed a complete set of pipeline system, using the first explosion welding technology.
● Friction stitch welding
British Welding Institute (TWI) in the mid 80s of last century developed a set of friction for the underwater environment, stud welding systems. The system has the equivalent of 600 m water depth pressure tested, the results show that the welding results from water depth, and has been proved that the system can effectively use the ROV (underwater robot). Recent development is the attempt to underwater friction stud welding friction welding the extension to have the stitched seam friction stitch welding. Beijing Institute of Petrochemical Technology now has started research in this area and obtained the support of National Natural Science Foundation.
5 Underwater welding technology trends in the 21st century
Though, the above method of underwater welding has been since its emergence, have to rely on their respective strengths in a particular area has been applied. But for now the research of underwater welding underwater welding can not fully meet the requirements of the future construction should be done focuses on the following aspects:
(1) From the welding metallurgy and welding quality assurance point of view, dry underwater welding is most favorable, so in recent years, high-pressure dry underwater welding technology is further developed, but still can not meet the actual demand. At present, the theoretical study for high-voltage arc is not very complete, multi-information fusion technology to achieve intelligent control of the welding process has become the field of high pressure dry welding a new topic.
(2) Underwater welding robot as the particularity of the work environment, an increase of underwater welding robot application difficulty. The future of underwater welding robot should be able to complete the welding of the pretreatment, welding and weld inspection work, therefore, should strive to do, including the precise positioning of underwater robot, robot arm motion control technology, based on visual sensor spatial location of the weld system detection, tracking and underwater welding quality control aspects of the work.
(3) Welding simulation technology to enable the emergence and development of welding technology is undergoing from experience to science, from qualitative to quantitative leap. In recent years, numerical simulation of welding technology in depth, breadth, but the simulation of underwater welding is relatively lagging behind, should pay attention and speed up the numerical simulation.
(4) Using computer simulation technology, than in the actual physical model of the installation, commissioning, testing and so the workload is much smaller, and the cycle is short, less investment, show many advantages. In recent years, it developed in the welding process, welding equipment, control systems development and improvement of all aspects of the research application. By welding simulation, help to the idea of a new program, and can find problems early, and this is an area should be studied later.
With the emergence of new requirements of underwater welding and the development of science and technology, the new method of underwater welding and welding tools will continue to emerge and display their unique advantages. Looking ahead, the move towards high-tech underwater welding technology will achieve greater glory.
水下焊接技术发展史
水下焊接技术是开发海洋、开采海底石油以及组装、维修诸如采油平台、输油管线和海底仓等大型海洋结构的关键技术之一, 也是舰船应急修理、海上救助、桥梁架设等工作的必要技术手段。核电是世界电力发展的趋势，在核电站内部，核反应堆压力容器（RPV）因为长期在水中工作，容易受到应力腐蚀裂纹的破坏，核电结构修复时，会遇到很多挑战。为了减少工作人员所受的核辐射，经常会采用水下焊接方法。水下焊接的分类一般将水下熔焊分为三大类: 湿法、干法和局部干法。其中干法又可以分为高压干法水下焊接和常压干法水下焊接。局部干法则包括排水罩式、高压水帘式、钢刷式、移动气箱式和等离子弧 MIG 局部干法等。采用的焊接方法一般有药皮焊条焊接, GTAW,GMWA以及 FCAW 。水下焊接除熔焊之外还有爆炸焊和 FSW ( friction stitch welding 摩擦叠焊) , 这两种方法都属于固相连接技术。以下为水下焊接的发展历程：
1 水下湿法焊接技术
1802 年, 一位名叫 Humphrey的学者指出电弧能够在水下连续燃烧, 即指出了水下焊接的可能性, 然而其实际应用却是在 100 多年以后, 在不可能把结构物移到陆地上进行焊接的情况下才做到的。1917 年,英国海军船坞的焊工采用水下焊接的方法来封堵位于轮船水下部分漏水的铆钉缝隙, 这是水下焊接的首次应用。第 一篇正式发表的关于水下焊接研究工作的论文, 是在 1933 年由 Hibshrman 和 Jensen 共同完成的。1932 年, Khrenov 发明了厚药皮水下专用焊条,在焊条外表面涂有防水层, 使水下焊接电弧的稳定性得到了一定程度的改善。到第二次世界大战结束时, 水下焊接技术在打捞沉船等方面已经占有重要地位。1971 年, Humble 石油公司对墨西哥湾钻采平台的水下焊接修理工作是水下焊接技术第一次应用于海洋石油工程。1985 年产生了第一批经过认可的潜水焊工,并制定了水深小于 100m 的水下湿法焊接工艺。1987 年, 水下湿法焊接技术在核电厂不锈钢管道的修理工作中得到应用。上世纪 90 年代, 随着要求修理的水下工程结构的增多以及船坞修理成本的增加,湿法焊接技术得到了进一步的发展。水下焊条的发展对水下湿法焊接的应用起着重要的作用。英国 Hydroweld 公司发展了多种水下焊条,取得了很好的实用效果。美国专利焊条—7018`s 焊条药皮上有一层铝粉, 水下焊接时能产生大量的气体,避免焊缝金属受到侵蚀。德国 Hanover 大学基于渣-气联合保护对熔滴过渡过程的影响和保护机理研制开发了双层自保护药芯焊条。通常水下湿法焊接的水深不超过 100 m, 目前努力的方向是实现 200 m水深湿法焊接技术的突破。早在上世纪 50 年代, 水下湿法焊条电弧焊就已经在我国得到应用。上世纪 60 年代我国开始自行开发水下专用焊条。华南理工大学研制的水下焊条在 30 m水深以内可以获得良好的焊接性能。
2 水下干法焊接技术
● 水下高压干法焊接技术
高压干法水下焊接的设想是 1954 美国首先提出的, 1966 年正式用于生产, 主要用于海底管道的修复。目前最大使用水深在 300 m 左右。该焊接方法中, 气室底部是开口的, 通入气压稍大于工作水深压力的气体, 把气室内的水从底部开口处排出, 焊接是在干的气室中进行的。一般采用 MIG 焊或 TIG 焊,是当前水下焊接中质量最好的方法之一, 基本上可达到陆上焊缝的水平。上世纪 70 年中期, 无人高压焊接研究装置开发成功。德国、挪威、美国、英国都在上世纪 90 年代开始此类研究并建立了无人高压焊接研究中心。从上世纪 80 年代中期开始, 一些研究中心就开始研究 300~500 m 水深的 GTAW 自动焊接系统和工艺, 或者是检验 500~1000 m水深替换性焊接技术的适应性了。现在法国、德国、挪威、美国的高压焊接研究中心的实验舱作业压力都可以达到相当于1000 m 水深。从上世纪 90 年代开始石油公司的作业已经开始进入更深的水域。第一个在这种水深下进行作业的公司应该是巴西石油公司 (即巴西国家石油公司) , 其在亚马孙盆地的作业水深达到 1 000 m。在我国, 随着海洋石油工业的发展, 迫切需要开发具有自主知识产权的高压干法焊接技术。在 2002 年的国家“863”计划中就有关于水下高压干法焊接技术的研究项目。由中国海洋石油工程公司、北京石油化工学院、石油大学、上海交通大学、哈尔滨工程大学联合研发设计的最大焊接水深为 60 m。目前, 项目基本完成, 即将进行海试。
● 水下常压干法焊接技术
水下高压干法焊接的焊接质量虽然较好, 但其局限性较大, 尤其是随着水深的增加, 电弧周围的气压不断增加, 容易破坏电弧的稳定性而产生焊接缺陷。而且在没有达到焊接全自动化的情况下, 需要潜水焊工的辅助操作, 如果水深超过潜水极限或者潜水成本过高则无法实施。在技术水平还无法解决这些问题的时候, 为了克服水下高压干法焊接的不足, 1977 年制造出水下常压干法焊接设备。1977年, 法国 LPS公司首先采用这种方法在北海水深150 m 处成功地焊接了直径 426 mm的海底管道。我国目前还没有水下常压干法焊接设备。
3 水下局部干法焊接技术
水下局部干法焊接技术有很多方法。上世纪 70年代后期, 哈尔滨焊接研究所在上海海难救助打捞局和天津石油勘探局的协助下, 开发了水下局部排水CO2 气体保护焊接技术, 简称 LD- CO2 焊接法, 属于排水罩式局部干法, 采用此方法可以完成多项水下施工任务。高压水帘式是由日本应用的一种方法, 为了克服水帘式的一些缺点, 日本又将其发展为钢刷式。移动气箱式于 1968 年由美国首先提出, 后由美英跨国公司应用于生产。法国最近还研究了一种旋罩式的水下局部干法焊接技术。另外, 等离子弧 MIG 局部干法水下焊接也是一种很有前途的局部干法焊接技术。
4 水下固相连接技术
● 爆炸焊
在上世纪 70 年代后期, 位于福内斯巴罗的英国水下管道工程公司研制成功了 1 套完整的管道修补系统, 首次采用了爆炸焊技术。
● 摩擦叠焊
英国焊接研究所 ( TWI) 在上世纪 80 年代中期开发了 1 套用于水下环境的螺柱摩擦焊系统。该系统已经在相当于 600 m 水深的压力下进行试验, 结果表明焊接效果不受水深影响, 而且业已证明, 该系统可以有效地使用 ROV (水下作业机器人)。最近的发展是试图把水下摩擦焊由螺柱摩擦焊扩展到具有缝合焊缝的摩擦叠焊。目前北京石油化工学院已经开始了此方面的研究工作并获得了国家自然科学基金的支持。
5 水下焊接技术在 21 世纪的发展趋势
虽然上述各种水下焊接方法自从其出现以来，都依靠其各自的优势 在特定的方面得到了应用。但从目前来看 水下焊接的研究还不能完全满足水下焊接施工的要求 未来应从以下几个方面做重点研究：
（1）从焊接冶金和保证焊接质量的角度看，干法水下焊接是最为有利的，所以，近年来高压干法水下焊接技术得到了进一步的发展，但仍然不能满足实际的需求。目前，对于高压电弧的理论研究还不十分完整，如何采用多信息融合技术达到对焊接过程的智能监控也已成为高压干法焊接领域的新课题。
（2）由于水下焊接机器人工作环境的特殊性，增加了水下焊接机器人的应用难度。未来水下焊接机器人应该能够完成焊缝的预处理、焊接及焊缝检测工作，因此，要努力做好包括水下机器人的精确定位技术、机器人手臂的运动控制技术、基于视觉传感系统的焊缝空间位置的检测、跟踪以及水下焊接质量控制等几个方面的工。
（3）焊接模拟技术的出现及发展使焊接技术正在发生着由经验到科学，由定性到定量的飞跃。近年来，焊接数值模拟技术不断向深度、广度发展，但对水下焊接的模拟研究还比较滞后，应重视和加快这方面的数值模拟研究。
（4）采用计算机仿真技，比在实际物理模型上的安装、调试、试验等工作量要小得多，并且周期短，投资少，显示出许多优点。近年来，它在焊接工艺的制定、焊接设备的研制以及控制系统的改进等方面的研究中都有应用。通过焊接仿真，有助于构思新方案，并能提前发现存在的问题，这也是以后应当研究的一个领域。
随着水下焊接新需求的出现以及科学技术的发展，新的水下焊接方法和焊接手段将会不断地涌现并显示它们的独特优势。展望未来，迈向高科技领域的水下焊接技术必将取得更大辉煌。
