Sand Casting Method for Medium Pressure 22nd Stator Blade of H-Class Combined Cycle Steam Turbine

Abstract

The sand casting method for the medium-pressure 22nd stage stationary blade of H-stage combined cycle steam turbine of the present invention comprises the following steps: (1) process design, including mold design; pouring position and pouring and riser design; cold iron system design; sprue cup design; Exhaust groove design; (2) selection and control of raw and auxiliary materials, including sand selection, coating selection and charge pretreatment; (3) pouring, including hot-type hot pouring and control of molten steel temperature and pouring temperature; (4) heat treatment, including normalizing and tempering Fire treatment; ⑸ chemical composition testing; ⑹ mechanical performance testing; ⑺ product acceptance. The invention adopts the sand casting method with low cost, short cycle and wide adaptability to replace the investment casting process, which simplifies the manufacturing process, shortens the production cycle, reduces the manufacturing cost, and reduces the pollution to the environment. The medium pressure No. 22 The quality of the stage stator vane has reached the same quality requirement as that of the investment casting process; the international competitiveness of the product has been improved.

Description

technical field [0001] The invention relates to the technical fields of sand casting and heat treatment, in particular to a sand casting method for the medium-pressure 22nd-stage stationary vane of an H-stage combined cycle steam turbine. Background technique [0002] The sand casting method of the medium pressure 22nd stage stator vane of the H-class combined cycle steam turbine belongs to the sub-project of the research project "Production and manufacture of important parts of the H-class combined cycle steam turbine", and the applicant unit is responsible for the research project. There is no domestic precedent for the manufacturing process of the 22nd stage stator blade of the medium pressure H-stage combined cycle steam turbine. Previously, the medium-pressure 22nd-stage stator blades of H-stage combined cycle steam turbines used in my country were all imported from abroad. However, foreign companies use the investment casting process to manufacture the medium pressure...

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Problems solved by technology

In order to occupy the market, it is necessary to innovate products, reduce costs, and deliver quickly. Therefore, the investment casting process described above has been difficult to meet the requirements of the market and production enterprises

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