Analysis of surface treatment process of stainless steel castings: How can professional factories improve durability and aesthetics?

In the field of industrial manufacturing, the performance of stainless steel castings not only depends on the material itself,Surface treatment processIt also directly affects its corrosion resistance, service life and appearance quality. Many users often ignore this link when choosing a stainless steel casting factory, while professional factoriesTechnology accumulationandCraftsmanship detailsJust that can make a significant difference. This article will analyze common surface treatment methods and reveal the hidden advantages of professional factories.

1. Why is surface preparation important?

Stainless steel castings may produce oxide scale, burrs or micro cracks during the casting process. If not properly treated, they will accelerate corrosion or reduce the structural strength. For example, if the surface of the valve body in chemical equipment is rough, it is easy for residual media to cause pitting corrosion. Professional factories will passMultiple processing stepsEnsure castings meet industry standards (such as ASTM A967).

2. Four core processes of professional factories

① Sand blasting\/shot blasting

• effect:Remove oxide layer and enhance coating adhesion.

• Advantages: Professional factories control the abrasive particle size (such as 80 mesh-120 mesh) and spray angle to avoid excessive wear of the base material.

② Pickling passivation

• effect: Remove free iron ions and form a passivation film.

• Difference: Small workshops may simplify the process, but regular factories will strictly operate according to concentration (such as 20% nitric acid plus 5% hydrofluoric acid) and time to ensure uniformity.

③ Electrolytic polishing

• Applicable scenarios: Medical equipment, food machinery and other fields that require high surface finish.

• Technical threshold: It is necessary to accurately control the current density (such as 15-30A\/dm²) and electrolyte temperature, otherwise it will easily lead to excessive corrosion.

④ Special coating (such as PTFE spraying)

• added value: To improve wear resistance or anti-sticking, professional factories can provide third-party coating performance testing reports.

3. How can users identify the real level of the factory?

• Look at the equipment: The investment in equipment such as automated sandblasting lines and constant-temperature pickling tanks represents process stability.

• Ask the case: Request to provide successful cases in the same industry (such as shipbuilding, pharmaceuticals) and observe the processing details.

• Test performance: It is required to take samples for salt spray test (such as no red rust after 500 hours) or roughness test (Ra less than or equal to 0.8μm).

4. Conclusion

Although surface treatment is an "invisible" link of stainless steel castings, it directly affects the value of the product. Choosing a factory with mature technology can not only extend the life of parts, but also reduce subsequent maintenance costs. It is recommended that users give priority to inspecting the factory when purchasing.Process documentsandactual sample, rather than just focusing on quotes.