SRIF undertakes research and development of special steel materials (heat-, wear-and corrosion-resistant) , foundry CAD, AOD refining technology and equipment concerned. For many years the institute has got a series of important achievements of special steel materials, steel casting technology, heat treatment, etc. The new type, high performance stainless steel grades used for power stations have become the main grades in the national hydraulic tubine manufacturing industry. The properties of newly developed high yield strength ratio stainless steel have already reached the advanced level in the world.
　　The production base of special steel castings, which takes 3,000 sq. m, is equipped with 1 set of 2 ton medium frequency induction electric furnace, 1set of AOD furnace and many modern analysis instruments.
　　SRIF has supplied many advanced manufacture technology and premium castings to large hydraulic power stations at home and abroad, such as Three-gorge hydraulic power station.

Sand-cast Special Steel Castings
    The special steel castings are manufactured by utilizing electric-furnace plus AOD duplexing technique, which can maintain the Ni4 series stainless steel content up to the requirements of commercial applications yet limiting the content of impurity and gas within a minimum level( [P,S] ≤0.04%,[N] ≤70ppm,,[O] ≤40ppm). Thanks to the special heat treatment, the strength, hardness and yield-tensile ratio of castings produced with low carbon lath martensite are greatly enhanced. In recent years, the technology has been successfully applied in manufacturing of flow passages components for hydro-turbine, such as wicket gate, Francis crown, Francis band, Kaplan and Francis blade with a wide range of sizes, Pelton, Kaplan and Francis turbine runner etc. The product capacity is 1000 tons per year. Other special steel products include the castings with boron applied in nuclear power station and all components of heat-resistant, corrosion-resistant and wear-resistant materials.

Pelton turbine runner

Francis turbine runner

Francis turbine blade

Kaplan turbine blade

Francis runner crown

Francis runner band

ESC furnace, 3000KVA

AOD refining vessel

 
AOD refining vessel

The AOD was an effective tool for controlling chemistry. Carbon content could be held to limits low enough to permit improvements in weldability. Level of sulfur, oxygen, hydrogen and nitrogen could also be driven down, thus increasing the toughness of AOD-refined materials. The company can manufacture AOD vessel and is charge of installation and debugging in site and personnel train.

Heat treatment furnace
The company has several heat treatment furnaces. The largest with capacities of 30 tons is heated by oil and computer-controlled, ensuring an accurate vessel and even temperature in all castings, the rest by electricity. Control equipment and thermocouples are regularly calibrated.

Quality assurance
Quality Inspection Center of SRIF owns all kinds of advanced test instruments. They can analyze chemical composition of various metals and castings, and test mechanical properties, microstructures, technology and NDT of products. ISO 9000 quality assurance system guarantees: only products after being strictly inspected and being acceptable can be delivered to our customers.

3-D profile line inspection of blade

Inspectors and customer are detecting castings