LowCostEB - Reducing the cost of electron beam welding for improved productivity of heavy manufacturing sectors

**_主要用于发电的“厚截面”钢结构的需求强劲且不断增长。全球79%的电力是由热过程产生的，其中常规发电厂提供全球电力供应的62%以上，其余17%是通过核裂变过程产生的，预计这一比例将增加（IEA，2015）。火电厂在主回路的许多部分使用大量厚截面（> 20 mm）部件;泵和阀体、辅助系统和其他安全关键部件。此外，英国的海上风电需求需要1,000多个结构（塔架和基础）或每年100万吨的钢材。大型金属结构的制造通常需要高完整性、厚截面、焊接;通常用于安全关键应用的结构（例如压力容器/蒸汽提升设备、航空航天部件等）。基于电弧的焊接技术是简单工程钢的首选，但将这些工艺应用于高性能先进合金和其他材料时存在局限性。基于电弧的工艺只能焊接到~2- 3 mm的深度，因此需要多道焊接;这增加了制造时间（有时每个焊接接头需要数十或数百道），成本并增加了焊接缺陷的机会以及所需的检查和返工量。为了降低成本，需要显著缩短该制造时间。_**电子束（EB）焊接一次可焊接0.1 mm至200 mm，无需昂贵的填充焊丝，使用更少的工艺气体，并可减少烟雾暴露-因此可以实现无与伦比的生产率提高（对于非常厚的截面制造，1，000倍）.CVE在过去7年中开发了“EBFlow”系统，并已开始商业化;这创造了一个局部真空工艺头，目标是离风制造，并将焊接时间从6,000小时减少到200小时，相当于降低了85%以上的成本。LowCostEB项目将使用这种方法（和学习），通过应用低成本的“本地室”系统来消除对真空室和专用屏蔽的要求。该项目将部署一个由剑桥真空工程（CVE）组成的团队，为高完整性制造TWI开发定制的功率束焊接解决方案（一家专门从事焊接和性能测试的RTO）和Stainless Metalcraft（一个最终用户制造商的例子）。该联盟将开发和评估LowCostEB系统，以提高材料利用率，开发设计，以最大限度地提高制造效率，并建立使经济和生产效益最大化的制造方法。

**_The demand for 'thick section' steel structures, primarily in power generation, is strong & growing._**Globally 79% of electricity is generated by thermal processes, in which conventional power plants provide over 62% of global electricity supply and the remaining 17% is by nuclear fission processes and this is expected to increase (IEA, 2015). Thermal power plants make use of a large number of thick section (\\\>20mm) components for many parts of the primary circuit; pump and valve bodies, ancillary systems and other safety critical components. Furthermore, off-shore wind demand in the UK requires \>1,000 structures (towers and foundations) or 1m tonnes of steel p.a. to be cost-effectively fabricated.The fabrication of large metallic structures typically requires high-integrity, thick section, welding; often for structures that are for safety critical applications (e.g. pressure vessels/steam raising plant, aerospace parts, etc). Arc-based welding techniques are first choice for simple engineering steels, but there are limitations in applying these processes to high performance advanced alloys and other materials. Arc-based processes can only weld to a depth of ~2-3mm, and thus multi-pass welding is needed; this increases manufacturing time (sometimes requiring tens or hundreds of passes per welded joint), costs and increases the chance of weld defects and the amount of inspection and re-work needed.**_To reduce cost this manufacturing time needs to be significantly reduced._**Electron beam (EB) welding can weld from 0.1mm to \>200 mm in a single pass, without costly filler wires, uses less process gas and can reduce fume exposure -- and thus can achieve unrivalled productivity improvements (\>1,000x for very thick section fabrications).CVE has over the last 7 years developed and has begun commercialising the 'EBFlow' system; which creates a local-vacuum process head, targeting off-wind fabrication, and reduces this welding time from 6,000hrs to <200hrs, equivalent to a reduction in cost of over 85%.**_The LowCostEB project will use this approach (and learning) to remove the requirement for a vacuum chamber and dedicated shielding through the application of low-cost 'local-chamber' system._**This project will deploy a team comprising Cambridge Vacuum Engineering (CVE) who develop bespoke power beam welding solutions for high integrity fabrications, TWI (an RTO specialising in welding and performance testing) and Stainless Metalcraft (an example end-user fabricator).The consortium will develop and evaluate of the LowCostEB system to improve material utilisation, develop designs for maximising manufacturing efficiency, and establish fabrication methods maximising the economic and production benefits.