Stainless Steel Precision Casting

In the field of precision casting, austenitic stainless steel 304 is the most versatile choice due to its balanced corrosion resistance, formability, and weldability. This is attributed to its stable 18-8 chromium-nickel austenitic structure, but it is susceptible to pitting and intergranular corrosion in chloride-containing environments, and its strength is relatively low.

As an upgraded version, stainless steel 316 offers excellent resistance to chloride ion corrosion due to the addition of molybdenum. The low-carbon 316L variant further avoids welding sensitization issues. However, the inclusion of precious metals significantly increases material costs, which is a primary consideration for its application.

For applications requiring excellent machinability, stainless steel 303 is an ideal choice. It improves machinability by adding sulfur or selenium, but this simultaneously disrupts the continuity of the material matrix, resulting in noticeably lower corrosion resistance and toughness compared to other austenitic grades.

Martensitic stainless steel 410 can achieve good comprehensive mechanical properties and certain corrosion resistance through heat treatment, at a lower cost, thanks to its approximately 13% chromium content. However, its corrosion resistance is limited, and its weldability is poor, making it suitable primarily for mild environments.

For higher hardness, stainless steel 420 achieves excellent wear resistance and polishability by increasing carbon content. However, the higher carbon content consumes chromium in the matrix, thereby compromising its corrosion resistance and increasing brittleness.

440C represents the peak hardness of martensitic stainless steels, with its extremely high carbon and chromium content enabling exceptional hardness after quenching. However, this also results in very poor corrosion resistance, high brittleness, and increased processing difficulty and costs.