Some nickel alloys are generalists. Hastelloy B-3 is not one of them: it's built almost entirely around one job, standing up to hydrochloric acid at any concentration and any temperature, better than nearly anything else available, and it does that by leaving chromium out of the recipe almost entirely. That same lack of chromium is what makes it the wrong choice the moment an oxidizing agent enters the picture. USA Piping Solution supplies Hastelloy B-3, also called Alloy B3, as seamless pipe and tube to ASTM B622 and welded pipe to ASTM B619, all in UNS N10675. For oxidizing or mixed-chemistry service, our Hastelloy C22 or Hastelloy C276 pages are the better fit.
Specifications
| Specification | Details |
|---|---|
| Standard | ASTM B622 / ASME SB622 (seamless pipe & tube) · ASTM B619 / ASME SB619 (welded pipe) · ASTM B626 / ASME SB626 (welded tube) |
| UNS | N10675 |
| DIN / Werkstoff | 2.4600 |
| Type | Nickel-molybdenum alloy, third generation of the Hastelloy B family |
| Form | Seamless and welded pipe and tube |
What B-3 Is Built For, and What to Avoid
Molybdenum, not chromium, does the work in this alloy. That's exactly why it excels at hydrochloric acid, sulfuric acid, acetic acid, phosphoric acid, and other reducing, non-oxidizing media, at any concentration and temperature in the case of HCl, better than almost any chromium-bearing alloy can manage. It's also why the same alloy performs poorly the moment the chemistry turns oxidizing.
- Strong in: hydrochloric acid (all concentrations and temperatures), sulfuric acid, acetic acid, phosphoric acid, and other non-oxidizing reducing media.
- Avoid for: any process with an oxidizing component, including dissolved oxygen at certain conditions, ferric or cupric ions, or oxidizing acids.
- Specific caution: iron and copper salts accelerate corrosion sharply in HCl service. Don't let B-3 piping contact iron or copper components upstream where those salts can form.
If your process has any oxidizing character or you're not fully certain, Hastelloy C22 is built to handle both oxidizing and reducing environments and is the safer default.
Why B-3 Replaced B-2
The original Hastelloy B and later B-2 alloys had the same core HCl resistance B-3 has, but B-2 is prone to forming brittle secondary phases as soon as it's heated, welding included, which often meant a full solution-annealing cycle just to restore ductility after fabrication. B-3's chemistry was optimized specifically to delay that reaction, so it can go into service in the as-welded condition for most vessels and piping instead of requiring that extra heat treatment step. Same HCl performance, meaningfully less fabrication risk.
Have a Drawing or Datasheet for HCl Service? Send It Over →
Applications
- Hydrochloric Acid Handling: reaction vessels, piping, and process equipment across the full concentration and temperature range, the alloy's defining use.
- Sulfuric, Acetic & Phosphoric Acid Service: chemical processing equipment in reducing acid environments.
- Vacuum Furnace Components: parts requiring stability in reducing atmospheres at elevated temperature.
- Herbicide & Insecticide Production: process equipment in agrochemical manufacturing.
- Ethylene Glycol & Ethylbenzene Production: piping and reactors in petrochemical processes.
- Valves, Pumps & Fasteners: components in reducing-environment service where HCl or similar resistance is required.
Testing, Certification & Availability
Every order ships with mill test certification and full material traceability; see our Quality Policy page for the full testing program we run across all grades. Send us your OD, wall thickness, and length requirement and we'll confirm current availability and lead time.
Related Products
- Hastelloy C276 Tubing
- Hastelloy C22 (Alloy 22) Pipes & Tubes
- Hastelloy Pipes & Tubes
- Nickel Alloy Pipes & Tubes
Frequently Asked Questions
Can Hastelloy B-3 be used in oxidizing environments?
Not recommended. Its low chromium content, 1 to 3%, means it lacks the passive film that protects chromium-bearing alloys in oxidizing media. For oxidizing or mixed-chemistry service, see our Hastelloy C22 page instead.
What's the difference between Hastelloy B-3 and B-2?
B-3 has the same core HCl resistance as B-2 but with significantly better thermal and structural stability, meaning it resists forming brittle phases during welding and can typically be used in the as-welded condition without a separate solution-annealing step.
Is Hastelloy B-3 suitable if my process has trace iron or copper contact?
Use caution. Iron and copper salts, which can form when HCl contacts iron or copper components, accelerate corrosion of B-3 significantly. Keep the alloy isolated from iron or copper contact points in the system.
What sizes are available in Hastelloy B-3 pipe and tube?
Send us your OD, wall thickness, and length requirement and we'll confirm current mill availability and lead time.