我们做什么
Citric and nitric acid processes available
Citric and nitric acid processes available
Removes free iron and weld contamination
Removes free iron and weld contamination
Restores chromium oxide passivity
Restores chromium oxide passivity
Performed after machining and welding
Performed after machining and welding
Certified to ASTM A967 and A380
Certified to ASTM A967 and A380
Improves performance in food and medical use
Improves performance in food and medical use
材料
| Stainless 304 and 316 |
| Stainless 17-4 PH |
| Duplex stainless |
| Machined and welded stainless assemblies |
| Medical-grade stainless parts |
关键规格
| 项目 | 参数 |
|---|---|
| Standards | ASTM A967, ASTM A380 |
| Process | Citric or nitric acid |
| Materials | 300 series and 400 series stainless |
| Thickness change | None |
| Testing | Copper sulphate and ferroxyl tests |
| Lead time | 3–6 working days |
表面处理与后加工
Followed by cleaning and packing
Followed by cleaning and packing
Combined with electropolishing
Combined with electropolishing
Certification documented
Certification documented
常见问题解答
Why passivate after welding?
Welding burns chromium away from the surface and leaves scale and iron contamination, both of which become corrosion initiation sites. Passivation removes them and restores the protective layer.
Citric or nitric acid?
Citric is safer to handle and increasingly preferred, while nitric is specified in some aerospace and nuclear standards. We select according to your specification.
Does passivation change dimensions or appearance?
No. It removes only surface contamination, leaving dimensions and appearance unchanged, which is why it is safe on finished precision parts.
More in this section
Anodizing
Type II and Type III anodizing for aluminium: clear, black and colour finishes with improved corrosion and wear resistance, thickness from 5 to 50 µm.
Hard Anodizing
Type III hard anodizing builds a 25-50 µm ceramic-like oxide layer with up to 500 HV surface hardness for wear-critical aluminium parts.
Bead Blasting
Glass bead blasting for a uniform satin finish on metal and plastic parts. Hides tool marks, prepares surfaces for coating and gives a premium matte look.
Sand Blasting
Sand blasting for surface cleaning, descaling and roughening. Removes rust, scale, old coating and oxide before welding, painting or bonding.
Polishing
Mechanical polishing to mirror and optical finishes: Ra down to 0.05 µm for mould cavities, light guides, medical parts and decorative surfaces.