Analysis of 5 key processes in stainless steel casting factories, technical points that buyers must read

When purchasing stainless steel castings, many companies tend to only focus on price and delivery time, but ignore the core process in the production process. In fact, the core competitiveness of a strong stainless steel casting factory is often reflected in the control of key processes. Today, we will analyze the five core processes of stainless steel casting factories to help buyers make more informed choices.

1. Smelting process: raw materials determine the performance of castings

The quality of stainless steel castings first depends on the smelting process. Regular manufacturers will useAOD (argon oxygen decarburization method)orVOD (vacuum deoxygenation method)Refining is carried out to ensure the purity of molten steel and reduce the impurity content. At the same time, strict controlThe proportion of carbon, chromium, nickel and other elements, to ensure the corrosion resistance and mechanical properties of the castings. Inferior castings often lead to defects such as pores and slag inclusions due to substandard smelting processes.

2. Casting process: the key to affecting the molding of castings

Commonly used casting methods in stainless steel casting factories includeSand casting, investment casting (lost wax casting)andMetal mold casting.in:

• sand castingSuitable for large-scale, simple-structure castings with lower cost but higher surface roughness.

• investment castingIt is suitable for castings with complex shapes and high requirements, such as pump valves, impellers, etc., and can ensure high dimensional stability.

• Metal mold castingSuitable for mass production, the castings have better density, but the mold cost is higher.

Buyers should choose the appropriate casting process based on product requirements to avoid quality problems caused by process mismatch.

3. Heat treatment process: the core step to improve the performance of castings

Stainless steel castings usually need to beSolution treatmentoraging treatment, to eliminate internal stress and improve corrosion resistance and mechanical strength. For example:

• 304, 316 and other austenitic stainless steelsNeed to proceed1050 degrees Celsius 1100 degrees Celsius solid solution treatment accelerates cooling, to ensure corrosion resistance.

• Duplex stainless steel (such as 2205)then need to proceedSolid solution plus aging treatment, to optimize strength and toughness.

If the heat treatment process is not in place, the casting may suffer from problems such as intergranular corrosion and increased brittleness, which will affect its service life.

4. Surface treatment process: determines the appearance and corrosion resistance of castings

The surface treatment of stainless steel castings directly affects its aesthetics and corrosion resistance. Common processes include:

• Sand blasting\/shot blasting:Remove oxide scale and improve surface adhesion.

• Pickling passivation: Remove free iron, form a passivation film, and enhance corrosion resistance.

• electropolishing: Suitable for medical applications with high gloss finish requirements.

Buyers need to choose the appropriate surface treatment method according to the application scenario (such as chemical industry, food, marine environment).

5. Non-destructive testing process: ensure zero defects in castings

Regular stainless steel casting factories will use X-ray testing (RT), ultrasonic testing (UT), penetrant testing (PT) and other methods for quality control to ensure that there are no cracks, pores and other defects inside the castings. Especially key components such as pressure-bearing parts and valves must undergo strict testing before leaving the factory.