1.4401 Stainless Steel: Less than 2% Molybdenum? It Could Be Fake 316!
Leave a message
1.4401 Stainless Steel Procurement Pitfall Guide: Mo Content Below 2%? It Might Be Fake 316!
In harsh corrosive environments, 316 stainless steel (EN 1.4401) is the material of choice due to its molybdenum (Mo) content. However, the market is flooded with "fake 316"-produced by reducing Mo content (<2%) or mixing in 304 stainless steel, severely compromising corrosion resistance.
1. Mo Content in 1.4401 Stainless Steel
Standard Composition:
316 stainless steel contains 2.0–2.5% Mo, which is essential for resisting chloride attack (e.g., seawater, salt solutions) and non-oxidizing acids (e.g., sulfuric acid).
Core Function:
Mo enhances the passive film, increasing pitting resistance over 3× higher than 304 stainless steel. In salt spray testing, its lifespan exceeds 2,000 hours without visible corrosion.
Risk Warning:
So-called "316" with Mo < 2% may fail within a year in marine or chemical settings, with repair costs 5–10× the original material cost.
2. Three-Step Detection Method for 1.4401 Stainless Steel
Check the Material Certificate
Require the supplier to provide an EN 10204 3.1 inspection certificate clearly indicating:
Mo ≥ 2.0%
Cr: 16.5–18.5%
Ni: 10–13%
Cross-verify the heat number with the delivered goods.
On-Site Spectroscopy Test
Use a portable XRF spectrometer for instant testing (results in 30 seconds).
Authentic 316 should show Mo content between 2.0–2.5%.
Reject any batch below this range.
Weld Quality Test (For Welded Pipes)
Request intergranular corrosion test reports per ASTM A262 Practice E.
Fake 316 is prone to weld cracking due to insufficient Mo.
Tip: Before bulk purchasing, randomly select 3 samples and send them to a third-party lab (e.g., SGS). Ensure accurate analysis of Mo, Ni, and Cr content-all three must meet spec.
3. Real-World Case: Costly Mistake in a Chemical Project
A chemical plant sourced low-cost "316" piping without verifying Mo content. Just six months later, chloride corrosion caused through-wall failures, resulting in over ¥500,000 in losses due to shutdown.
Lab tests revealed the material had only 1.2% Mo-it was actually 304 stainless steel falsely labeled as 316. Legal action was taken against the supplier, but the project faced serious delays.
Conclusion: Mo Content Is the "Authentication Code" of 316 Stainless Steel
When sourcing 316 stainless steel, your first move should be a spectrometer test of the Mo content-it's the most direct and effective anti-counterfeiting measure.
Contact us now to request GNEE's free sample testing and material suitability consultation, ensuring long-term reliability and eliminating the risk of counterfeit products!info@gneestainless.com
