Inconel 625 Procurement: 5 Authenticity Checks
Date: 2026年9月17日 Categories: News Views: 395
By Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier | ISO 9001:2015 | Est. 2012
Contact: sales@hangboalloy.com | hangbo@nickel-alloy.com | WhatsApp (Lisa): +86 13611656360
Quick Answer: What Is the Biggest Risk When Buying Inconel 625?
Inconel 625 (UNS N06625) is one of the most widely counterfeited nickel alloys because it is expensive and visually indistinguishable from cheaper grades. The most common substitution is 316L or 904L sold as 625 — both are bright, non-magnetic, and similar in density. The protection is straightforward: verify molybdenum (8-10%) and niobium (3.15-4.15%) by PMI, confirm the delivery condition (annealed), and demand an EN 10204 3.1 certificate with a traceable heat number. This whitepaper gives 5 checks.
Why Inconel 625 Is Targeted for Substitution
- Price gap: 625 costs 6-10x 316L and 2x 904L.
- Visual identity: Bright, non-magnetic, similar density to stainless steels.
- Specification confusion: Many buyers accept "625 grade" without ASTM/ASME designation.
- Nb is hard to detect: Cheap XRF units often cannot measure niobium — a favorite loophole.
The 5 Checks (Do These Before Payment)
| Check | What It Proves | Method / Threshold |
|---|---|---|
| 1. PMI for Mo + Nb | Chemistry = N06625 | Mo 8-10%, Nb 3.15-4.15%, Ni >= 58% |
| 2. Iron check | Not a stainless substitute | Fe <= 5% (316L has ~65% Fe) |
| 3. Hardness / condition | Annealed delivery | 150-220 HB typical |
| 4. MTC + heat number | Traceability | EN 10204 3.1 + mill heat number, ASME SB443/B446 |
| 5. Third-party inspection | Independence | SGS/BV/TUV witness PMI + certificate review |
Warning: Require a calibrated XRF or wet-chemistry analysis for niobium — many handheld units report Nb as "not detected" even in genuine 625.
Common Substitution Scenarios
| "625" Delivered | PMI Signature | Detection |
|---|---|---|
| 316L (S31603) | Fe ~65%, Mo 2-3% | Fe too high, Mo too low → reject |
| 904L (N08904) | Fe ~45%, Mo 4-5% | Fe too high, no Nb → reject |
| Alloy 20 (N08020) | Cu 3-4%, Fe ~37% | Cu present, Fe too high → reject |
| 800H (N08810) | Fe ~45%, no Mo | No Mo, high Fe → reject |
Specification Reference
| Parameter | Value |
|---|---|
| UNS | N06625 |
| ASTM Plate/Sheet | B443 |
| ASTM Bar | B446 |
| ASTM Tube | B444 / B704 / B705 |
| Annealing | 1090-1200C / rapid quench |
| Delivery condition | Annealed, pickled or bright |
Price Reference (2026, EXW)
| Form | Fair Price |
|---|---|
| Plate (10-20mm) | \$50-78/kg |
| Round Bar | \$48-75/kg |
| Tube | \$60-95/kg |
| Below \$35/kg | Suspicious — likely 316L/904L |
FAQ
Q1: How do I verify Inconel 625?
PMI for Mo 8-10% and Nb 3.15-4.15%, Fe <= 5%, plus EN 10204 3.1 MTC with heat number.
Q2: Can 904L be mistaken for 625?
Visually yes. PMI Fe content separates them: 904L has ~45% Fe, 625 has <= 5%.
Q3: Why is niobium important?
Nb 3.15-4.15% is essential to 625's strength and corrosion resistance — a no-Nb material is not 625.
Q4: What hardness should annealed 625 have?
Typically 150-220 HB.
Q5: What is the correct annealing temperature?
1090-1200C with rapid quench.
Q6: Which ASTM standard applies to plate?
ASME SB443 / ASTM B443 for plate, sheet and strip.
Q7: What does Shanghai Hangbo provide?
625 in plates, bars, tubes, and fittings with PMI reports and EN 10204 3.1 MTC. SGS/BV/TUV third-party inspection available.
Contact & Complete Product Range
Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier
Email: sales@hangboalloy.com | WhatsApp (Lisa): +86 13611656360 | www.nickel-alloy.com
All Grades
Ni: NI200-N6 | Monel: 400-502, K-500, R-405 | Inconel: 600-740H, X-750, 725 | Incoloy: 800-27-7MO | Hastelloy: C-276-HYBRID-BC1, N | Super Austenitic: 904L-AL-6XN | Chromium-Rich: Alloy 33 | High-Strength Stainless: Nitronic 50/60, PH13-8Mo | Chlorination: Alloy 45 | Nimonic: 75-263 | Haynes: 25-HR-160 | RA: 330/333 | Precision: 1J22-4J45 | High-Strength: 18Ni250-AerMet100 | Heating: Cr20Ni80/60 | Specialty: Alloy 20-602CA
Product Forms: Bars(6-500mm) | Tubes(OD 6-610mm) | Plates(0.1-100mm) | Forgings | Welded Pipes | Fittings | Wire(0.05-10mm) | Strip(0.02-4.0mm)
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