Hastelloy G-50 (UNS N06950) - Sour Gas Resistant Alloy Supplier of Bars, Tubes & Forgings | Shanghai Hangbo Alloy Group

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 Hastelloy G-50?

Hastelloy G-50 (UNS N06950) is a nickel-chromium-molybdenum alloy with 20% chromium and 9% molybdenum, specifically engineered for sour oilfield service (H₂S + CO₂ + chlorides) where it combines excellent resistance to stress-corrosion cracking (SCC), pitting, and sulfuric acid attack. It is qualified per NACE MR0175 and is the benchmark material for sour-gas wellhead components, completion equipment, and downhole tooling. Shanghai Hangbo Alloy Group supplies Hastelloy G-50 as round bars, tubes, and forgings.

Industry Pain Point: Deep sour wells (15%+ H₂S, 60,000 ppm chlorides) are the graveyard of 316L and duplex stainless — chloride SCC and sulfide stress cracking destroy them within months. C-276 survives but its 16% molybdenum makes it 2-3x the cost of G-50. G-50 delivers C-276-class sour service resistance at a 30-40% cost saving, optimized through balanced Cr-Mo-W-Fe chemistry that suppresses both pitting and SCC simultaneously.

Key Properties at a Glance

Product Overview

Hastelloy G-50 is the oilfield specialist of the Hastelloy G-family (G-30, G-35, G-50). Where the G-30/G-35 grades target acid processing, G-50 was tuned specifically for the combined challenge of sour oil and gas production: simultaneous resistance to chloride pitting, H₂S-induced sulfide stress cracking (SSC), and stress-corrosion cracking in produced fluids.

The alloy's balanced chemistry is the key: 20% Cr provides passivity, 9% Mo (with 1.5% W) provides pitting resistance, 17% Fe provides cost reduction, and the tight copper control (0.5-2.0%) optimizes H₂S performance without degrading the acid resistance. The result is a single alloy that passes the full suite of NACE MR0175 qualification tests while remaining forgeable, weldable, and machinable for complex wellhead components.

Shanghai Hangbo Alloy Group supplies Hastelloy G-50 in bars (for downhole tooling and valve stems), tubes (for completion strings), and forgings (wellhead housings, tubing hangers).

Executive Standards

Chemical Composition (wt.%)

Mechanical & Physical Properties

Room-Temperature (Solution-Annealed 1120C/WQ)

Physical Properties

Heat Treatment

Solution Annealing: 1120C (2050F), rapid water quench or air cool. No precipitation hardening.

Corrosion Performance (Sour Service)

Industry Applications

Quality Assurance: 7-Stage

1. Raw Material: Ni, Cr, Mo, W verified by OES.
2. VIM Melt: Cr +/-0.3%, Mo +/-0.2%, Cu +/-0.1% control.
3. Hot Working: 1150-1200C, finishing >=1000C, reduction >=4:1.
4. Solution Anneal: 1120C verified, hardness <=100 HRB.
5. SSC Test: NACE TM0177 Method A verification per lot on request.
6. NDE: 100% UT bars >=50mm; ET/hydro tubes. PMI every piece.
7. Documentation: EN 10204 3.1 MTC + NACE MR0175 statement. SGS/TUV witness.

Frequently Asked Questions

Q1: What is Hastelloy G-50 used for?

Sour oilfield wellhead components, downhole completion equipment, subsea manifolds, and sulfuric acid handling — anywhere NACE MR0175 sour service is required at lower cost than C-276.

Q2: G-50 vs C-276?

C-276: 16% Mo, broader acid resistance, 2-3x cost. G-50: 9% Mo + 2% W, NACE-qualified sour service, 30-40% cheaper. Choose G-50 for oilfield sour duty.

Q3: G-50 vs G-30/G-35?

G-30/G-35 target wet-process phosphoric acid and oxidizing acids. G-50 targets sour gas + chloride environments. Different application families.

Q4: Is it weldable?

Yes, with matching filler. Excellent weldability with proper heat input control.

Q5: What is the maximum service temperature?

~400C for structural service (NACE limits apply for sour service).

Q6: What is the price?

$45-75/kg EXW. Contact sales@hangboalloy.com.

Q7: Product forms?

Bars (6-300mm), tubes (OD 10-219mm), forgings, plates. SGS available.

Q8: Is it magnetic?

No — fully austenitic, non-magnetic.

Q9: What heat treatment?

Solution annealing at 1120°C, rapid cool. No aging.

Q10: Does it meet NACE?

Yes — NACE MR0175 / ISO 15156 qualified.

Q11: What is the density?

8.22 g/cm3.

Q12: Does Shanghai Hangbo ship internationally?

Yes — FOB/CIF/DAP to 40+ countries.

Q13: What standards apply?

ASTM B581 (bar), B582 (plate), B619/B622 (tube), B564 (forging).

Q14: Why copper?

Copper (0.5-2.0%) optimizes performance in H₂S environments while maintaining acid resistance.

Q15: Can it replace Inconel 625 in sour service?

For NACE-qualified sour service, G-50 is the preferred choice; 625 has no NACE MR0175 sour qualification for high-stress applications.

Contact Shanghai Hangbo Alloy Group

Shanghai Hangbo Alloy Group - Complete Product Range

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)

SGS/BV/TUV. Contact: sales@hangboalloy.com | WhatsApp (Lisa): +86 13611656360 | www.nickel-alloy.com