[News Report] Fuan Heavy Industry Successfully Delivers the Integrated High- and Intermediate-Pressure Outer Casing Project for Mitsubishi Heavy Industries Steam Turbines

　　Recently, Liaoning Fuan Heavy Industry Co., Ltd. undertook the fabrication of the high- and intermediate-pressure outer cylinders for steam turbines manufactured by Mitsubishi Heavy Industries, Ltd. (MHI) of Japan. “Casting + Precision Machining” The integrated project has completed all manufacturing tasks and been successfully delivered. This follows the company’s previous successful completion of hydropower projects overseas, including those for GE in the United States, Voith in Germany, and Andritz in Austria. “Casting + Precision Machining” This integrated project represents another major breakthrough in the company’s overseas thermal power generation portfolio, marking the formal expansion of its end-to-end delivery capabilities—spanning from casting to precision machining—from the domestic market to the international arena.

　　The high- and intermediate-pressure outer casing of the Mitsubishi Heavy Industries steam turbine delivered this time is intended for large-scale thermal power generating units. It is an external pressure-containing, integrally supported, thermally expanded–positioned, steam-sealed and partitioned high-temperature, thick-walled cast steel outer pressure shell that, within a double-casing structural system, serves to control thermal stresses in the casing. During operation, it withstands high temperature and high pressure; the material is a high-temperature alloy steel casting capable of withstanding temperatures exceeding 570°C.
　　The precision finishing of the high- and intermediate-pressure outer casing of steam turbines has long been regarded as the “pinnacle of technology” in heavy machinery manufacturing and serves as the ultimate “touchstone” for evaluating a company’s precision machining capabilities. This component measures 5,500 mm in overall length, 3,400 mm in width, and features an internal cavity with a maximum diameter of 1,800 mm, all demanding exceptionally high machining accuracy: the flatness of the centerline joint surface must not exceed 0.02 mm—only one-third the diameter of a typical human hair; after the upper and lower halves are assembled, the step misalignment within the cavity must be less than 0.07 mm; the coaxiality of the bearing bores must be tightly controlled within 0.05 mm; and the radial dimensional deviation on either side of the centerline joint surface, as well as the deviation in the arc-top radius, must each remain within 0.05 mm. The internal cavity structure of this product is highly intricate, necessitating the use of multi-axis coordinated precision CNC technology to ensure form accuracy during machining. Moreover, the workpiece material is alloy steel, which exhibits significant cutting resistance; combined with the large overall dimensions of the component, machining is prone to deformation and cutting-induced vibration, making it extremely challenging to maintain dimensional accuracy and geometric tolerances. In addition, the service conditions for this component are severe and complex, placing stringent demands on the load-carrying capacity, long-term operational stability, and high-precision retention of the machining equipment. Even the slightest machining error can directly affect the safety, stability, and power-generation efficiency of the entire turbine unit, underscoring the high technical barriers and rigorous control standards throughout the entire manufacturing and machining process.
　　In the face of technical challenges, the Fuan Heavy Industry team persevered in overcoming obstacles and innovatively applied key technologies such as CNC simulation, precision measurement, and composite cutting tools, thereby establishing a closed-loop manufacturing process that spans from casting to finish machining. Through project implementation, the company has cultivated a highly skilled, cutting-edge team spanning process engineering, CNC machining, and quality control, established a robust technical system for the manufacture of core steam turbine components, and solidified its talent and technological foundations.

　　Project delivery represents a key achievement in Fuan Heavy Industry’s implementation of its “high-end casting + precision machining” strategy, consolidating collaborations with leading international companies, demonstrating its strength in the machining of high-precision components for million-kilowatt-class nuclear power units, and signaling that its equipment, processes, and quality management system have reached world-class standards. This milestone opens up new opportunities for expanding into the high-end equipment markets, including nuclear power.
　　From cast blanks to precision finished products, and from the domestic to the international market, Fuan Heavy Industry drives industrial upgrading through innovation, breaks through processing bottlenecks, and contributes to China’s self-reliance and controllability in critical equipment. Looking ahead, the company will continue to deepen its expertise in high-end manufacturing, focusing on the R&D of core components such as nuclear power high-pressure outer cylinders and hydropower runner wheels, leveraging artisanal dedication to promote high-quality development of the manufacturing sector and injecting robust momentum into the “dual carbon” goals.

　　Prepared by: Fang Zhen, Li Honghe
　　Proofread by: Xu Yuguang
　　Reviewed by: Li Jing, Qin Shuai
　　Published by: Wei Dan