Robust manufacturing technology for sodium-cooled fast reactor (SFR) components required development of various innovative welding technologies backed by thorough research. Construction of the 500 MWe Prototype Fast Breeder Reactor at Kalpakkam was preceded by extensive technology development which included planning and implementation of R&D on welding consumables and procedures and also technologies for fabrication of components with stringent specifications. To take on the challenges and establish robust manufacturing techniques for fabrication of all the structural components of the SFR, a close interaction among design, materials and non-destructive evaluation engineers, materials and welding consumable manufactures, and the fabrication industries had to be facilitated. Fabrication of SFR reactor vessels, steam generators, fuel sub-assemblies, etc., requires extensive welding. Activated tungsten inert gas (A-TIG) welding process together with activated flux was developed in-house. The same was successfully implemented on various SFR components. Online monitoring and control during welding was developed based on a computational intelligence methodology and deployed for obtaining near defect-free welded components. Plasma transferred arc welding process was used for deposition of a nickel-base alloy for hardfacing of SFR components, with improved resistance to high-temperature wear, especially galling of mating surfaces in liquid sodium environment. In order to substantially reduce carbon footprint, India has initiated a national mission programme for design, development and establishment of a 800 MWe Advanced Ultra-supercritical (AUSC) power plant having steam parameters of 710ºC/ 720ºC/ 310 bar. Success of this program heavily banks on development of materials and fabrication technologies that can sustain the extreme in-service conditions. Two important India-specific high-temperature tube materials were developed for the purpose, namely, 304HCu austenitic stainless steel (304HCu SS) and modified Alloy 617M. In addition, large cylindrical forgings of Alloy 617M of up to 800 mm diameter for turbine rotors were indigenously developed. R&D activities included development of welding consumables and welding procedure for TIG welding of tubes, including the 304HCu SS/Alloy 617M dissimilar joint. Based on the tensile and creep tests results, welding consumables for joining the tubes and their dissimilar joints were also finalized. Technology development also included dissimilar metal welding between Alloy 617M and 10Cr-steel forgings for turbine rotors. The dissimilar metal weld between 400 mm Alloy 617M and 10Cr-steel were produced by directly welding the two forgings using Alloy 617 filler wire using narrow-gap TIG welding process. Similarly, procedure for NG welding of superheater headers was also demonstrated. This paper discusses the Indian efforts toward development and deployment of welding technologies for fabrication of components for the Indian SFR-based nuclear power plant and the AUSC thermal power plant.

钠冷快堆（SFR）组件的可靠制造技术要求开发各种创新的焊接技术，并进行深入研究。在卡尔帕卡姆建造500 MWe原型快中子增殖堆之前，先进行了广泛的技术开发，包括规划和实施焊接材料和程序的研发，以及用于制造具有严格规格的组件的技术。为了应对挑战并建立强大的制造技术来制造SFR的所有结构部件，必须促进设计，材料和无损评估工程师，材料和焊接耗材制造商以及制造行业之间的紧密互动。SFR反应堆容器，蒸汽发生器的制造，燃料组件等需要大量焊接。内部开发了活性钨惰性气体（A-TIG）焊接工艺以及活性焊剂。在各种SFR组件上成功实现了同样的目的。焊接过程中的在线监视和控制是基于计算智能方法开发的，并用于获取几乎无缺陷的焊接组件。等离子转移弧焊工艺用于沉积SFR部件的镍基合金，以提高其抗高温磨损的能力，尤其是在液态钠环境中的配合表面的磨损。为了大幅减少碳足迹，印度发起了一项国家设计任务计划，开发和建立蒸汽参数为710ºC/720ºC/ 310 bar的800 MWe先进超超临界（AUSC）发电厂。该计划的成功很大程度上取决于可以维持极端使用条件的材料和制造技术的开发。为此，开发了两种重要的印度专用高温管材料，即304HCu奥氏体不锈钢（304HCu SS）和改性的617M合金。此外，本地开发了用于涡轮转子的直径最大为800 mm的617M合金大型圆柱形锻件。研发活动包括焊接材料的开发以及用于TIG焊管的焊接工艺，包括304HCu SS / Alloy 617M异种接头。根据拉伸和蠕变测试结果，最终确定了用于连接管子及其异种接头的焊接材料。技术发展还包括在617M合金和用于涡轮转子的10Cr钢锻件之间进行异种金属焊接。400 mm Alloy 617M和10Cr钢之间的异种金属焊缝是通过使用窄间隙TIG焊接工艺直接使用617合金填充焊丝焊接两个锻件而制成的。同样，还演示了过热器集管的NG焊接程序。本文讨论了印度在开发和部署用于印度SFR核电站和AUSC火力发电厂组件制造的焊接技术方面所做的努力。400 mm Alloy 617M和10Cr钢之间的异种金属焊缝是通过使用窄间隙TIG焊接工艺直接使用617合金填充焊丝焊接两个锻件而制成的。同样，还演示了过热器集管的NG焊接程序。本文讨论了印度在开发和部署用于印度SFR核电站和AUSC火力发电厂组件制造的焊接技术方面所做的努力。400 mm Alloy 617M和10Cr钢之间的异种金属焊缝是通过使用窄间隙TIG焊接工艺直接使用617合金填充焊丝焊接两个锻件而制成的。同样，还演示了过热器集管的NG焊接程序。本文讨论了印度在开发和部署用于印度SFR核电站和AUSC火力发电厂组件制造的焊接技术方面所做的努力。