Large tonnage steel castings are widely used in power plant, petrochemical industry, metallurgy, shipbuilding and other machinery and equipment manufacturing industries, which is an important symbol of the development level of national manufacturing industry.

At present, great progress has been made in the production of large steel castings in our country, but there are still obvious deficiencies in the quality of steel products. Several large steel castings have been produced, but quality problems often occur. So far, they do not have the technical ability to produce high-quality products. Some developed countries keep the production technology of large steel castings strictly secret, and even strictly restrict the export of products, so that large steel castings have become the main factor restricting the development of national economy.

Restriction analysis of the development of large steel castings in our country

Some high-quality key castings in our country still do not meet the quality requirements of domestic host and large technical equipment. Large-scale nuclear power equipment mainly produces large steel castings, such as nuclear power main pumps, steam turbine cylinder blocks and so on. Stainless steel, its quality requirements are extremely high, our country has not mastered independent production technology, mainly relies on imports.

Therefore, it is urgent to improve the level of basic research and technical development in order to produce high quality steel castings conforming to the standard and solve the problem of producing steel castings of 100 tonnage in equipment manufacturing.

At present, the development trend of domestic cast steel industry includes the following aspects:

1. Smelting molten steel, developing high purity molten steel technology, strictly controlling the smelting process, controlling sulfur, phosphorus and inclusions. The refining of molten steel is used to improve the quality of molten steel.

2. In the process of casting process design, computer simulation technology should be used to simulate the casting process and casting solidification, so as to optimize the casting process and improve the casting quality.

3. Closely follow the needs of transformation and development in the field of mechanical equipment, vigorously develop new casting materials, gradually replace imports, and improve the overall level of steel casting production.

4. Strengthen the adjustment and optimization of industrial structure to form a reasonable economic scale.

5. Strengthen technological progress, improve technological innovation ability, and carry out research on materials and processes for producing high-quality castings.

6. Introduce green casting technology, improve the level of clean production, and improve the mechanization and intelligent control level of the post-production process of steel castings.

Compared with the developed countries, there is a big gap in the overall production level of large-scale steel castings in the aspects of product types, technology level, quality level and production equipment. Due to the high quality requirements of large steel castings, the metallurgical technology of large steel castings is developing to high purity molten steel technology, so it is necessary to improve the control technology of composition uniformity, internal defects and dimensional accuracy. The production technology of large steel castings is developing to high - tech.