Stainless pipe fitting,stainless fitting,duplex stainless,31803,32750,32760,we are one of largest sour service stainless fitting supplier according to ISO 10156.
HAYNES® 188 alloy (UNS R30188) is a cobalt-nickel-chromium-tungsten superalloy that delivers an exceptional combination of high-temperature strength, long-term oxidation resistance up to 2000°F (1095°C), and outstanding resistance to sulfate-deposit hot corrosion. This versatile material is also highly resistant to molten chloride salts and gaseous sulfidation, making it a reliable choice for the most demanding chemical processing, power generation, and aerospace applications. Alloy 188 is readily fabricated and formed using conventional techniques and has been successfully used for both wrought and cast components.
Equivalent Designations
- PWA 1042
- Werkstoff 2.4683 / EN 2.4683
- AMS 5801 / AMS 5608
Applicable Specifications (HAYNES® 188 / UNS R30188)
| Product Form | Specification |
|---|---|
| Sheet, Plate & Strip | AMS 5608 |
| Billet, Rod & Bar | AMS 5772 |
| Forgings | AMS 5772 |
| Coated Electrodes | – |
| Bare Welding Rods & Wire | – |
| Seamless Pipe & Tube | – |
| Welded Pipe & Tube | – |
| Fittings | – |
UNS R30188 Chemical Composition
| Element | Weight % |
|---|---|
| Cobalt | 39 (Balance) |
| Nickel | 22 |
| Chromium | 22 |
| Tungsten | 14 |
| Iron | 3 max. |
| Manganese | 1.25 max. |
| Silicon | 0.35 |
| Carbon | 0.1 |
| Lanthanum | 0.03 |
| Boron | 0.015 max. |
ALLOY 188 Physical Properties (at 22 °C / 72 °F)
| Property | Metric | English |
|---|---|---|
| Density | 8.98 g/cm³ | 0.324 lbs/in³ |
| Modulus of Elasticity | 232 GPa | 33.7 Mpsi |
| Electrical Resistivity | 101.0 μohm·m | 39.6 μohm·in |
| Thermal Conductivity | 10.4 W/m·°K | 72 BTU·in/hr·ft²·°F |
| Coefficient of Thermal Expansion | 12.1 μm/(m·°C) | 6.7 μin/(in·°F) |
Typical Mechanical Properties – Room Temperature Cold-Worked
| Cold Worked % | Yield Strength | Ultimate Tensile Strength | Elongation % |
|---|---|---|---|
| 0 | 938 MPa (136 ksi) | 1324 MPa (192 ksi) | 34 |
| 20 | 1110 MPa (161 ksi) | 1544 MPa (224 ksi) | 5.6 |
| 37 | 1641 MPa (238 ksi) | 2013 MPa (292 ksi) | 4.1 |
| 50 | 1813 MPa (263 ksi) | 2165 MPa (314 ksi) | 3.3 |
| Values typical; 25.4 cm (10 in) gauge length. |
Elevated-Temperature Tensile Properties – Hot-Rolled & Solution-Annealed Plate
| Test Temp (°F/°C) | YS (ksi/MPa) | UTS (ksi/MPa) | Elong. % |
|---|---|---|---|
| RT / RT | 70.1 / 483 | 143.8 / 991 | 50.6 |
| 1000 / 538 | 45.7 / 315 | 120.6 / 832 | 60.3 |
| 1200 / 649 | 45.1 / 311 | 121.6 / 838 | 62.8 |
| 1400 / 760 | 43.6 / 301 | 84.1 / 580 | 85.6 |
| 1600 / 871 | 37.1 / 256 | 49.5 / 341 | 97.9 |
| 1800 / 982 | 19.2 / 132 | 27.2 / 188 | 102.6 |
| 2000 / 1093 | 9.6 / 66 | 13.9 / 96 | 87.1 |
Elevated-Temperature Tensile Properties – Cold-Rolled & Solution-Annealed Sheet
| Test Temp (°F/°C) | YS (ksi/MPa) | UTS (ksi/MPa) | Elong. % |
|---|---|---|---|
| RT / RT | 70.1 / 483 | 142.4 / 982 | 50.9 |
| 1000 / 538 | 44.8 / 309 | 117.4 / 809 | 58.8 |
| 1200 / 649 | 44.8 / 309 | 119.1 / 821 | 58.6 |
| 1400 / 760 | 43.8 / 302 | 81.6 / 563 | 81.8 |
| 1600 / 871 | 37.8 / 261 | 47.0 / 324 | 103.9 |
| 1800 / 982 | 18.2 / 125 | 25.4 / 175 | 81.0 |
| 2000 / 1093 | 8.5 / 59 | 12.4 / 85 | 49.7 |
Thermal Stability
Like solid-solution-strengthened superalloys (e.g., Alloy 625 or HASTELLOY® X), HAYNES® 188 alloy can precipitate a CO₂W Laves phase after prolonged high-temperature exposure, which may reduce tensile ductility and impact strength. However, Alloy 188 demonstrates significantly better thermal stability than the older HAYNES® 25 alloy. For applications where maximum thermal stability is critical, 230® alloy is recommended.
Room-Temperature Properties of Plate After Thermal Exposure
| Exposure Temperature | – | 0.2% Yield Strength | Ultimate Tensile Strength | Elongation | Impact Strength | ||||
| °F | °C | h | ksi | MPa | ksi | MPa | % | ft.- lbs. | J |
| 1200 | 650 | 0 | 65.0 | 450 | 140.0 | 965 | 56.0 | 143 | 194 |
| 8000 | 79.7 | 550 | 151.6 | 1045 | 29.1 | 23 | 31 | ||
| 1400 | 760 | 0 | 65.0 | 450 | 140.0 | 965 | 56.0 | 143 | 194 |
| 8000 | 74.0 | 510 | 147.9 | 1020 | 10.8 | 3 | 4 | ||
| 1600 | 870 | 0* | 70.1 | 485 | 146.0 | 1005 | 50.4 | 143 | 194 |
| 1000 | 70.7 | 490 | 157.5 | 1085 | 28.7 | 10 | 13 | ||
| 8000* | 64.5 | 445 | 147.4 | 1015 | 22.2 | 9 | 12 | ||
Welding & Forming
Alloy 188 offers good formability and welding characteristics. It can be forged or hot-worked after soaking at 2150°F (1175°C). Its excellent ductility also permits cold forming, but the alloy work-hardens rapidly—frequent intermediate annealing may be necessary for complex shapes. All hot- or cold-worked parts should be annealed and rapidly cooled to restore optimal properties. Welding processes include TIG, MIG, electron beam, and resistance welding, with good restraint-welding performance.
Heat Treatment
Wrought HAYNES® 188 alloy is supplied in the solution heat-treated condition. Standard solution treatment: 2125–2175°F (1163–1191°C) followed by rapid cooling or water quenching. Annealing below solution temperature can cause carbide precipitation that may alter properties.
Contact Us – Your Global Supplier of Alloy 188 Pipe Fittings & Flanges
We warmly welcome global customers to inquire about HAYNES® 188 alloy (UNS R30188) and our full range of specialty alloy pipe fittings, flanges, forged parts, and custom machining solutions. From material verification and full technical consultation to one-stop procurement, we support your chemical processing, power plant, environmental, and hydrometallurgy projects with reliable quality and on-time delivery.
Need a quote or more details?
Talk to our specialists today through our Contact Us page, and see our latest alloy fittings in action on our YouTube Channel.
