Foreign technology status: Hangzhou Steam Turbine Casting and Forging Co., Ltd. pointed out in the patent technical background of “a kind of gas turbine inlet cylinder and manufacturing process”, that a Japanese company provided a domestic company with a nodular cast iron inlet cylinder casting used for gas turbine had serious shrinkage defects in the finishing process after the supply was returned to the factory, and the defect location belongs to the inlet cylinder casting technology It is difficult to meet the requirements of the quality acceptance standard due to the serious shrinkage of the blade retaining ring. Although the gas turbine intake cylinder made of fcd450 material provided by a Japanese heavy industry basically meets the requirements of the standard, the casting price of the gas turbine is obviously higher than that of the same kind of castings in China due to market control, which increases the overall cost of the unit and directly weakens the competitive advantage in the fierce competition of new cost priority.
Domestic technology status: the investigation results of several major power main engine manufacturers show that at present, only a few domestic manufacturers have the ability to produce the inlet cylinder. A foundry company affiliated to a certain group in China has become the manufacturing center of gas turbine iron castings in China and even in the world a few years ago, but there are still many quality problems such as slag inclusion and sand inclusion in the castings. Three years ago, the company began to supply gas turbine inlet cylinder castings for an electrical company, but it was found in the inspection and subsequent finishing process after the purchase Different degrees of casting defects can not meet the quality requirements. A domestic company has been carrying out research and attempt on the casting technology of nodular cast iron into cylinder casting. During the three-year research and development process, about ten sets of castings have been produced, which have serious casting defects or unstable process, and have not achieved good results in manufacturing technology.
It shows that there are still great differences in the production and technology research and development of the gas turbine inlet cylinder castings among the domestic foundry manufacturers, and there are still some deficiencies in the research and development of the core casting technology of the inlet cylinder castings.