Corrosion resistance and stainless steel selection
Compare 304, 316, and martensitic stainless steels by environment, temperature, and manufacturing needs.
This guide is prepared for quick engineering review. Critical design decisions still require the relevant standard, supplier data, and engineering approval.
Problem / Objective
Stainless steel selection is not just a chromium percentage check. Chlorides, temperature, welding, cleaning chemicals, and surface roughness change corrosion behavior.
Assumptions
- Service environment and cleaning chemicals are known.
- Surface finish can be controlled.
- Mechanical strength and corrosion resistance are reviewed together.
Step by step method
- Classify the environment as dry, humid, chloride, or chemical.
- Compare common options such as 304 and 316.
- Define post-weld passivation needs.
- Write the surface roughness and cleanability target.
- Score cost and availability as the final check.
Common mistakes
- Assuming every stainless steel suits marine service.
- Forgetting heat affected zones and passivation after welding.
- Ignoring dirt retention on rough surfaces.
Related calculators
Related glossary terms
Quick FAQ
Question: What is the main difference between 304 and 316?
316 contains molybdenum and usually performs better in chloride environments.
Question: Can stainless steel rust?
Yes. Wrong environment, surface damage, or aggressive cleaning chemicals can cause local corrosion.
Question: Why passivate after welding?
It helps recover the protective surface layer and reduces corrosion risk.
Related engineering links
Calculators, terms, and companion guides that share the same engineering concepts.
Guides
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Titanium alloys guide
Evaluate Ti-6Al-4V and similar titanium alloys by weight, corrosion resistance, cost, and machinability.
Surface finishing methods guide
Compare coating, paint, anodizing, galvanizing, and passivation by environment, cost, and maintenance.
Glossary
Corrosion Resistance
Corrosion Resistance is a core engineering term. Definition, usage notes, and a practical example.
Surface Finishing
Surface Finishing is a core engineering term. Definition, usage notes, and a practical example.
Density
Density is a core engineering term. Definition, usage notes, and a practical example.
Ductility
Ductility is a core engineering term. Definition, usage notes, and a practical example.