Hastelloy B-3 Ni-Mo

Ni-Mo alloy, nominal weight %: Ni 65 min, Mo 28.5, Cr 1.5, Fe 1.5

Also known as UNS N10675, EN 2.4600, DIN NiMo29Cr, ASTM B333, ASTM B335, ASTM B564 · 5 more

Hastelloy B-3 (UNS N10675, W.Nr.

8 sources · Updated 2026-10-26 · CC BY 4.0

Evidence level

2 of 5

Lab-measured

Resist hot hydrochloric acid

0.29 mm/y, boiling 20 % HCl

Resist hot sulfuric acid

0.03 mm/y, boiling 50 % H2SO4

Resist chloride cracking

No cracking in 1,008 h

Carry load when hot

269 MPa yield at 538 °C

Stay tough when cold

453 J at -196 °C

Recipe, share of the weight

  • Ni minimum; the rest of the alloyNickel
  • Mo 28.5%Molybdenum
  • Cr 1.5%Chromium
  • Fe 1.5%Iron
  • W maximum 3Tungsten
  • Mn maximum 3Manganese
  • Co maximum 3Cobalt
  • Al maximum 0.5Aluminum
  • Ti maximum 0.2Titanium
  • Si maximum 0.1Silicon
  • C maximum 0.01Carbon
  • Nb maximum 0.2Niobium
  • V maximum 0.2Vanadium
  • Cu maximum 0.2Copper
  • Ta maximum 0.2Tantalum
  • Zr maximum 0.01Zirconium

Best for

Hot hydrochloric and sulfuric acid service in reducing conditions: 0.29 mm/y in boiling 20 % HCl and 0.03 mm/y in boiling 50 % H2SO4 in Haynes lab tests

Weakest at

Oxidising conditions: ferric or cupric salts, wet chlorine gas and hypochlorite bleach (no chromium to protect it), and cracking in welds after more than about 7 % cold work without re-annealing

Risk at a glance

  • People Low. Fume and dust
  • If it fails High. Cracking in the weld region after cold work
  • Corrosion Severe. Not suitable where oxidising conditions occur.

Quick facts: Ni-Mo

Key properties of Ni-Mo
PropertyValueBasis
Density9.22 g/cm³1 sourced value
Yield strength400 to 421 MPa2 sourced values across conditions
Tensile strength862 to 883 MPa2 sourced values across conditions
Young's modulus216 GPa1 sourced value
Thermal conductivity11.2 W/(m·K)1 sourced value
Thermal expansion (CTE)10.6 to 11.8 ppm/K2 sourced values across conditions
Melting point1,370 to 1,418 °C1 sourced value
Specific heat373 J/(kg·K)1 sourced value
Electrical resistivity0.0000014 Ω·m1 sourced value

What is the density of Hastelloy B-3 (Ni-Mo)?

Hastelloy B-3 (Ni-Mo) has a density of 9.22 g/cm³. The source and test conditions are listed in the properties table on this page.

What is the thermal conductivity of Hastelloy B-3 (Ni-Mo)?

Hastelloy B-3 (Ni-Mo) has a thermal conductivity of 11.2 W/(m·K). The source and test conditions are listed in the properties table on this page.

What is the coefficient of thermal expansion of Hastelloy B-3 (Ni-Mo)?

Hastelloy B-3 (Ni-Mo) has a coefficient of thermal expansion of 10.6 to 11.8 ppm/K. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.

What is the melting point of Hastelloy B-3 (Ni-Mo)?

Hastelloy B-3 (Ni-Mo) has a melting point of 1,370 to 1,418 °C. The source and test conditions are listed in the properties table on this page.

What is the yield strength of Hastelloy B-3 (Ni-Mo)?

Hastelloy B-3 (Ni-Mo) has a yield strength of 400 to 421 MPa. The range covers 2 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.

What are the other names and codes for Hastelloy B-3 (Ni-Mo)?

Hastelloy B-3 (Ni-Mo) is also written as UNS N10675, EN 2.4600, DIN NiMo29Cr, ASTM B333, ASTM B335, ASTM B564. Each code is printed in the source listed beside it in the designations table.

What is Hastelloy B-3 (Ni-Mo) used for?

Uses recorded in the sources include Reaction vessels for pure, reducing acid service; Process equipment in acetic acid, methyl methacrylate and agrochemical plants.

Why it exists

Hastelloy B-3 is a nickel-molybdenum alloy made for acids. With a nominal 28.5 % molybdenum and at least 65 % nickel, Haynes says it resists pure hydrochloric, hydrobromic and sulfuric acids, and Rolled Alloys says it resists hydrochloric acid at all concentrations and temperatures. Its main advantage over the older B-2 alloy is thermal stability: it forms unwanted phases more slowly, so it stays ductile through fabrication. Its density is 9.22 g/cm3 and its melting range is 1370 to 1418 °C. The Hastelloy brand belongs to Haynes International.

Where it's used

Chemical plants

Haynes names reaction vessels for pure, reducing acid service as its main use. Rolled Alloys lists acetic acid production (initial phase, with an iodide catalyst), methyl methacrylate production with hot 98 % sulfuric acid, and herbicide, insecticide, ethylene glycol and ethylbenzene production.

Spacecraft, rockets and satellites

No spacecraft, rocket or satellite use of B-3 was found in the sources read. A Wikipedia line about the Space Shuttle refers to the original Hastelloy B grade, not B-3, and is not counted.

Recipe

Ni-Mo alloy, nominal weight %: Ni 65 min, Mo 28.5, Cr 1.5, Fe 1.5; maxima W 3, Mn 3, Co 3, Al 0.5, Ti 0.2, Si 0.1, C 0.01, Nb 0.2, V 0.2, Cu 0.2, Ta 0.2, Zr 0.01 (Haynes nominal composition, weight %)

Ni-Mo alloy made as wrought plate, sheet, strip, billet, bar, wire, pipe and tube (Haynes brochure). Wrought products are supplied solution heat-treated (mill annealed) unless otherwise specified, and the annealing temperature is 1066 °C with a water quench (Haynes H-2104E). Rolled Alloys gives the specification ranges Ni 65 min, Mo 27 to 32, Cr 1 to 3, Fe 1 to 3 and maxima for the rest. The parts below are the Haynes nominal composition.

What Ni-Mo is made of
IngredientShare of the weightWhat it does
Nickel Ni minimum; the rest of the alloy matrix metal, gives the austenitic structure and corrosion resistance
Molybdenum Mo 28.5% main alloying element, gives resistance to reducing acids
Chromium Cr 1.5% minor addition; Haynes notes little chromium is present
Iron Fe 1.5% minor element
Tungsten W maximum 3 minor element, improves stability
Manganese Mn maximum 3 minor element
Cobalt Co maximum 3 minor element
Aluminum Al maximum 0.5 minor element
Titanium Ti maximum 0.2 minor element
Silicon Si maximum 0.1 minor element
Carbon C maximum 0.01 kept low so the alloy can be used as welded
Niobium Nb maximum 0.2 minor element
Vanadium V maximum 0.2 minor element
Copper Cu maximum 0.2 minor element
Tantalum Ta maximum 0.2 minor element
Zirconium Zr maximum 0.01 minor element

Weight shares are as printed in the sources.

What it can do

Resist hot hydrochloric acid

0.29 mm/y, boiling 20 % HCl

At boiling, 20 wt% hydrochloric acid corrodes B-3 at 0.29 mm/y in Haynes laboratory tests with reagent-grade acid. The Alloy at a Glance gives 11 mpy, against 15 mpy for B-2 and more than 20,000 mpy for 316L.

Resist hot sulfuric acid

0.03 mm/y, boiling 50 % H2SO4

In boiling 50 wt% sulfuric acid B-3 corrodes at 0.03 mm/y in the same Haynes tests.

Resist chloride cracking

No cracking in 1,008 h

In boiling 45 % magnesium chloride, stressed U-bend samples of B-3 showed no cracking in six weeks, while 316L cracked in 2 hours.

Carry load when hot

269 MPa yield at 538 °C

Sheet yield strength falls from 421 MPa at room temperature to 269 MPa at 538 °C (0.2 % offset, datasheet values).

Stay tough when cold

453 J at -196 °C

Plate Charpy V-notch energy is 479 J at room temperature and 453 J at -196 °C, three tests each.

Weigh

9.22 g/cm3

measured

Density is 9.22 g/cm3 at room temperature.

How it compares

The 2020 Alloy at a Glance sets B-3 against B-2, 316L and Monel in boiling acids. In 20 % hydrochloric acid B-3 corrodes at 11 mpy, B-2 at 15 mpy, 316L at more than 20,000 mpy and Monel at 1587 mpy. In 50 % sulfuric acid B-3 is at 1.1 mpy, B-2 at 1.0 mpy, 316L at more than 20,000 mpy and Monel at 185 mpy. In the same boiling-acid test B-2 is about as good as B-3 in sulfuric acid, so the gain is mainly in thermal stability and in hydrochloric acid.

The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Other materials are shown beside it; each was measured under its own conditions, so open its page before comparing closely. Compare every grade in the family.

Benchmarks
MeasurementNi-MoIN718 (UNS N07718)IN625 (UNS N06625)FeNi36C-22C-276 (UNS N10276)X (UNS N06002)UNS N07214H230 (UNS N06230)UNS N08800Alloy 825 (UNS N08825)Alloy 600 (UNS N06600, W.Nr. 2.4816)Alloy 601Alloy 617X-750 (UNS N07750)Fe-Ni-CoAlloy 400 (UNS N04400)K-500NiNi3Al, NiAlNiBe2Ni-alloysUNS N07090 (W. Nr. 2.4632)UNS N07001
Capacity and energy
Charpy V-notch impact energy, plate, room temperatureValue printed in a manufacturer datasheet479 J10no datano datano data469 J479 J140 Jno datano data122 Jno data82.4 Jno datano datano datano datano datano datano datano datano datano datano datano data
Charpy V-notch impact energy, plate, -196 °CValue printed in a manufacturer datasheet453 J11no datano datano data469 J479 J140 Jno datano data122 Jno data82.4 Jno datano datano datano datano datano datano datano datano datano datano datano data
Thermal behavior and safety
Melting rangeRange printed in a manufacturer datasheet1370 to 1418 °C1260 °C1290 to 1350 °C1427 °C1357 to 1399 °C1323 to 1371 °C1260 to 1355 °C1355 to 1400 °C1301 to 1371 °C1357 to 1385 °C1370 to 1400 °C1354 to 1413 °C1360 to 1411 °C1330 to 1380 °C1393 to 1427 °C1450 °C1300 to 1350 °C1315 to 1350 °C1455 °Cno data1195 to 1325 °C1425 °C1370 °C1330 to 1360 °C
Thermal conductivity, room temperatureValue printed in a manufacturer datasheet11.2 W/m.°C79 BTU·in/ft²·h·°F9.8 W/m°C72.85 Btu·in/(hr·ft²·°F)10.1 W/(m·K)10.5 W/m.°C9.2 W/(m·K)12 W/m-°C8.9 W/(m·°C)11.5 W/m°C11.1 W/(m·K)14.9 W/(m·K)11.2 W/(m·K)13.4 W/(m·K)83 Btu/in./hr/sq ft/°F17.5 W/m °K22 W/m°C17.5 W/m °C70.3 W/(m·K)no data48 W/(m·K)13 W/(m·K)11.47 W/(m·K)19.1 W/(m·°C)
Specific heat, room temperatureValue printed in a manufacturer datasheet373 J/kg.°C435 J/kg °C410 J/(kg·K)515 J/(kg·K)410 J/(kg·K)427 J/kg.°C486 J/(kg·K)452 J/kg-°C397 J/kg·°C460 J/kg·°C440 J/(kg·K)444 J/kg °C448 J/(kg·K)419 J/(kg·K)0.103 Btu/lb/°F500 J/(kg. K)427 J/kg°C419 J/kg °C456 J/(kg·K)no datano data500 J/(kg·K)446 J/(kg·K)no data
Physical and electrical
Density, room temperatureValue printed in a manufacturer datasheet9.22 g/cm³0.297 lb/in38.44 g/cm³8.05 g/cm³8.69 g/cm³8.89 g/cm³8.22 g/cm³8.05 g/cm³8.97 g/cm³7.94 g/cm³8.14 g/cm³0.306 lb/in38.11 Mg/m38.36 g/cm³8.28 g/cm³8.36 g/cm³8.8 g/cm³8.45 g/cm³8.89 g/cm³7.5 g/cm³8.27 g/cm³8.2 g/cm³8.18 g/cm³8.19 g/cm³
Electrical resistivity, room temperatureValue printed in a manufacturer datasheet1.37 μohm.m725 ohm circ mil/ft129 µΩ-cm84 µΩ·cm1.14 µΩ·m1.23 μohm.m114.8 µohm-cm135.9 µohm-cm125 µohm-m0.989 µΩ·m112 µΩ·cm1.03 µΩ·m1.18 µΩ·m1.22×10^-4 Ω·cm731 ohm circ mil/ft49 μΩcm0.511 µΩ·m0.615 µΩ·m0.096 µΩ·mno data< 28.7 µΩ·cm45 µΩ·cm1.18 µΩ·m1.24 µΩ·m
Hardness, plate, solution annealed95 HRBW12no datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano datano data
Other measurements
Mean coefficient of thermal expansion, 25 to 100 °CValue printed in a manufacturer datasheet10.6 μm/m.°C8.91 ppm/°F12.8 ppm/°C1.3 ppm/K12.4 ppm/K11.2 μm/m.°C13.9 µm/(m·K)14.6 µm/m-°C11.8 ppm/K14.4 µm/m/°C13.9 ppm/K10.4 ppm/K13.75 µm/m/°C11.6 µm/(m·K)7 10-6 in./in./°F5.86 10-6/°C14.2 µm/m°C13.7 10-6/°C13.3 ppm/Kno data14.5 ppm/K8 ppm/K12.7 µm/(m·K)14.3 µm/m·°C
Mean coefficient of thermal expansion, 25 to 500 °CValue printed in a manufacturer datasheet11.8 μm/m.°C8.91 ppm/°F12.8 ppm/°C1.3 ppm/K12.4 ppm/K11.2 μm/m.°C13.9 µm/(m·K)14.6 µm/m-°C11.8 ppm/K14.4 µm/m/°C13.9 ppm/K10.4 ppm/K13.75 µm/m/°C11.6 µm/(m·K)7 10-6 in./in./°F5.86 10-6/°C14.2 µm/m°C13.7 10-6/°C13.3 ppm/Kno data14.5 ppm/K8 ppm/K12.7 µm/(m·K)14.3 µm/m·°C
Dynamic modulus of elasticity, room temperatureValue printed in a manufacturer datasheet216 GPa129 ksi x 10^3207.5 GPa140 GPa206 GPa205 GPa205 GPa218 GPa209 GPa196.5 GPa196 GPa214 GPa206.5 GPa211 GPa31 10^3 ksi138 kN/mm226 10^3 ksi179 GPa205 GPa200 GPa195 to 210 GPano data204 GPa211 GPa
Yield strength 0.2 % offset, sheet, room temperatureValue printed in a manufacturer datasheet421 MPa2171 ksi60 to 95 ksi40 ksi> 310 MPa356 MPa340 MPa577 MPa417 MPa250 MPa338 MPa170 to 345 MPa292 MPa340 MPa> 105 ksi> 200 N/mm225 to 50 ksi276 to 414 MPa105 to 210 MPano data280 to 480 MPa280 MPa752 MPa586 MPa
Ultimate tensile strength, sheet, room temperatureValue printed in a manufacturer datasheet862 MPa3201 ksi120 to 150 ksi65 ksi690 to 950 MPa792 MPa760 MPa975 MPa837 MPa590 MPa662 MPa550 to 690 MPa675 MPa710 MPa> 165 ksi450 to 585 N/mm275 to 90 ksi621 to 758 MPa380 to 520 MPa2300 MPa660 to 900 MPa500 MPa1175 MPa1027 MPa
Elongation, sheet, room temperatureValue printed in a manufacturer datasheet53 %426 %30 to 60 %35 %> 45 %61 %48.9 %37.3 %47.3 %17 %45 %35 to 55 %46 %62 %> 20 %> 25 %35 to 60 %20 to 35 %40 to 55 %no data> 30 %35 %30 %43 %
Yield strength 0.2 % offset, plate, room temperatureAverage printed in a manufacturer datasheet400 MPa5171 ksi60 to 95 ksi40 ksi> 310 MPa356 MPa340 MPa577 MPa417 MPa250 MPa338 MPa170 to 345 MPa292 MPa340 MPa> 105 ksi> 200 N/mm225 to 50 ksi276 to 414 MPa105 to 210 MPano data280 to 480 MPa280 MPa752 MPa586 MPa
Ultimate tensile strength, plate, room temperatureAverage printed in a manufacturer datasheet883 MPa6201 ksi120 to 150 ksi65 ksi690 to 950 MPa792 MPa760 MPa975 MPa837 MPa590 MPa662 MPa550 to 690 MPa675 MPa710 MPa> 165 ksi450 to 585 N/mm275 to 90 ksi621 to 758 MPa380 to 520 MPa2300 MPa660 to 900 MPa500 MPa1175 MPa1027 MPa
Elongation, plate, room temperatureAverage printed in a manufacturer datasheet58 %726 %30 to 60 %35 %> 45 %61 %48.9 %37.3 %47.3 %17 %45 %35 to 55 %46 %62 %> 20 %> 25 %35 to 60 %20 to 35 %40 to 55 %no data> 30 %35 %30 %43 %
Yield strength 0.2 % offset, sheet, 538 °CValue printed in a manufacturer datasheet269 MPa8171 ksi60 to 95 ksi40 ksi> 310 MPa356 MPa340 MPa577 MPa417 MPa250 MPa338 MPa170 to 345 MPa292 MPa340 MPa> 105 ksi> 200 N/mm225 to 50 ksi276 to 414 MPa105 to 210 MPano data280 to 480 MPa280 MPa752 MPa586 MPa
Ultimate tensile strength, sheet, 538 °CValue printed in a manufacturer datasheet676 MPa9201 ksi120 to 150 ksi65 ksi690 to 950 MPa792 MPa760 MPa975 MPa837 MPa590 MPa662 MPa550 to 690 MPa675 MPa710 MPa> 165 ksi450 to 585 N/mm275 to 90 ksi621 to 758 MPa380 to 520 MPa2300 MPa660 to 900 MPa500 MPa1175 MPa1027 MPa

Why choose it, and why not

Good for

  • Reducing hydrochloric and sulfuric acid service: 0.29 mm/y in boiling 20 % HCl and 0.03 mm/y in boiling 50 % H2SO4 in Haynes lab tests.
  • Welded parts in the as-welded condition, because the carbon content is 0.01 % or less.
  • Equipment that must resist chloride cracking: no cracking in 1,008 h in boiling 45 % magnesium chloride.

Watch out for

  • Oxidising salts: ferric or cupric salts can cause rapid corrosion failure, and wet chlorine or hypochlorite is not withstood.
  • Cold work above about 7 % without re-annealing makes welds crack, sometimes only in service.
  • Ni4Mo can form between 500 and 900 °C; B-3 forms it more slowly than B-2 but is not immune.
  • No spacecraft, outgassing, radiation or atomic-oxygen data were found for this alloy.

Hastelloy B-3 is a nickel-molybdenum alloy for hot, non-oxidising acids, especially hydrochloric acid. It has a density of 9.22 g/cm3 and, as solution-annealed sheet, a room-temperature tensile strength of 862 MPa. It works well in reducing chemical plant, fails in oxidising salts and wet chlorine, and must be annealed after heavy cold work. No space or rocket use was found for this grade.

Technical details

For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.

Other names and standards

The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.

Other names and standards
SystemCodes
UNSN10675
EN2.4600
DINNiMo29Cr
ASTMB333 (plate, sheet and strip), B335 (billet, rod and bar), B564 (forgings), B622 (seamless pipe and tube), B619 (welded pipe and tube), B626 (welded tube), B366 (fittings)
Trade nameHASTELLOY® B-3®

Notes

The method, full conditions and any caveat for the numbered rows above.

Notes for the numbered rows
#MeasurementMethodConditionsCaveat
1Dynamic modulus of elasticity, room temperature—temperature room temperature (RT, as printed)measure dynamic modulus (not a static tensile test)unit in source 31.4 x 10^6 psi—
2Yield strength 0.2 % offset, sheet, room temperature—form sheet, 0.125 in (3.2 mm) thicktemper as supplied, mill annealed per datasheet text (the table does not print the condition)temperature room temperature (RT)measure 0.2 % offsetunit in source 61 ksi—
3Ultimate tensile strength, sheet, room temperature—form sheet, 0.125 in (3.2 mm) thicktemper as supplied, mill annealed per datasheet text (the table does not print the condition)temperature room temperature (RT)unit in source 125 ksi—
4Elongation, sheet, room temperature—form sheet, 0.125 in (3.2 mm) thicktemper as supplied, mill annealed per datasheet texttemperature room temperature (RT)—
5Yield strength 0.2 % offset, plate, room temperature—form plate, multiple thicknessestemper as supplied, mill annealed per datasheet texttemperature room temperature (RT)measure 0.2 % offset, average of 6 lots of plate from 3 heatsunit in source 58 ksi—
6Ultimate tensile strength, plate, room temperature—form plate, multiple thicknessestemper as supplied, mill annealed per datasheet texttemperature room temperature (RT)measure average of 6 lots of plate from 3 heatsunit in source 128 ksi—
7Elongation, plate, room temperature—form plate, multiple thicknessestemper as supplied, mill annealed per datasheet texttemperature room temperature (RT)measure average of 6 lots of plate from 3 heats—
8Yield strength 0.2 % offset, sheet, 538 °C—form sheet, 0.125 in (3.2 mm) thicktemper as supplied, mill annealed per datasheet texttemperature 538 °C (1000 °F)measure 0.2 % offsetunit in source 39 ksi—
9Ultimate tensile strength, sheet, 538 °C—form sheet, 0.125 in (3.2 mm) thicktemper as supplied, mill annealed per datasheet texttemperature 538 °C (1000 °F)unit in source 98 ksi—
10Charpy V-notch impact energy, plate, room temperature—form plate, 0.79 in (20 mm) thicktest Charpy V-notchtemperature room temperature (RT)number of tests 3unit in source 353 ft.lbf—
11Charpy V-notch impact energy, plate, -196 °C—form plate, 0.79 in (20 mm) thicktest Charpy V-notchtemperature -196 °C (-320 °F)number of tests 3unit in source 334 ft.lbf—
12Hardness, plate, solution annealedTypical value printed in a manufacturer datasheetform platetemper solution annealed (the table states all samples were solution annealed)test Rockwell B, tungsten indentertemperature room temperature—

Corrosion and compatibility

What happens when it meets other materials and environments.

Corrosion and compatibility
EnvironmentConcernWhat happens
Boiling 20 wt% hydrochloric acid moderate Moderate uniform corrosion in boiling 20 % hydrochloric acid.1
Boiling 50 wt% sulfuric acid low Low uniform corrosion in boiling 50 % sulfuric acid.2
Boiling 45 % magnesium chloride, stressed U-bend (chloride stress corrosion cracking) none No stress corrosion cracking in 1,008 hours.3
Boiling 60 wt% sulfuric acid after 1 h at 700 °C low No cracking after the 700 °C treatment in boiling 60 % sulfuric acid.4
All-weld-metal in 10 wt% hydrochloric acid at 93 °C moderate Weld metal corrodes at the same rate as wrought base metal in 10 % HCl at 93 °C.5
Oxidising media, ferric or cupric salts, wet chlorine gas and hypochlorite bleach severe Not suitable where oxidising conditions occur.6
Corrosion details
#EnvironmentDetailsTest conditions
1 Boiling 20 wt% hydrochloric acid Haynes gives 0.29 mm/y for 20 wt% HCl at boiling in reagent-grade acid under laboratory conditions. The Alloy at a Glance gives 11 mpy for B-3 in 20 % HCl, against 15 mpy for B-2, more than 20,000 mpy for 316L and 1587 mpy for Monel in the same boiling test. concentration 20 wt%temperature boilingbasis reagent-grade acid, laboratory corrosion jobs
2 Boiling 50 wt% sulfuric acid Haynes gives 0.03 mm/y for 50 wt% H2SO4 at boiling. The Alloy at a Glance gives 1.1 mpy for B-3 and 1.0 mpy for B-2 in 50 % sulfuric acid, against more than 20,000 mpy for 316L and 185 mpy for Monel. concentration 50 wt%temperature boilingbasis reagent-grade acid, laboratory corrosion jobs
3 Boiling 45 % magnesium chloride, stressed U-bend (chloride stress corrosion cracking) B-3, C-276 and 625 showed no cracking after 1,008 h (six weeks) in boiling 45 % magnesium chloride, while 316L cracked in 2 h and 254SMO in 24 h. test ASTM G 36, boiling 45 % magnesium chloride, stressed U-bendduration 1,008 h
4 Boiling 60 wt% sulfuric acid after 1 h at 700 °C U-bend specimens of B-3 annealed and then held 1 h at 700 °C showed no cracking in 24 h. B-2 with the same treatment cracked intergranularly after 3 h. concentration 60 % sulfuric acidtemperature boilingtreatment annealed plus 1 h at 700 °Cduration 24 h
5 All-weld-metal in 10 wt% hydrochloric acid at 93 °C Haynes tested all-weld-metal from MIG cruciform assemblies. Weld metal and wrought base metal both show 0.29 mm/y (11.4 mpy) in 10 % HCl at 200 °F (93 °C). In some other environments welds corrode faster than wrought metal, as the datasheet notes. concentration 10 wt%temperature 200 °F (93 °C)specimen all-weld-metal, MIG passes
6 Oxidising media, ferric or cupric salts, wet chlorine gas and hypochlorite bleach The alloy has no significant chromium, so Rolled Alloys says it should not be used in oxidising media or with oxidising salts such as ferric or cupric salts, and that it does not withstand wet chlorine gas or hypochlorite bleach. basis manufacturer statement, no rate given

Risks and side effects

Hazards to people, what happens when a cell overheats, and how the material is handled and stored.

For people

The main health route is metal dust and fume from welding, cutting or grinding. Solid metal is rated 0 on every HMIS scale in the Haynes SDS.

Solid metal
The Haynes SDS gives the solid article a health, flammability and reactivity rating of 0, 0, 0.
Dust and fume
Metal dust and fume from melting, welding, cutting or grinding can irritate the airways. Excessive inhalation of nickel can cause metal fume fever, and insoluble nickel compounds are linked to lung cancer.
Skin and sensitisation
The SDS lists H317 (skin sensitisation) and H334 (respiratory sensitisation) for the product group that includes B-3.

If it fails

These are the failure routes the sources describe. Each comes from a datasheet statement, not from a field failure record.

Cracking in welds
After more than about 7 % cold work without solution annealing, Haynes says B-3 is very susceptible to cracking in the welded region, which may show only in service.
Phase formation
Ni4Mo can form between 500 and 900 °C and lowers ductility and stress corrosion resistance. B-3 forms it more slowly than B-2.
Oxidising conditions
Ferric or cupric salts and wet chlorine or hypochlorite attack the alloy, which has almost no chromium to protect it.

Handling and storage

Anneal after forming
Solution anneal at 1066 °C, hold 10 to 30 minutes and water quench; re-anneal after outer-fibre elongation of 7 % or more.
Narrow hot-work window
Hot forging starts at 1232 °C and finishes at 982 °C, and the alloy work-hardens faster than austenitic stainless steel.
Filler metal
Use ENiMo-10 coated electrodes or ERNiMo-10 bare rod as matching filler metal.

Test details
The original wording and numbers from the sources, for readers who want them.

Failure risks

Failure risks
FailureTrigger and consequence
Cracking in the weld region after cold workhigh severityCold work greater than about 7 % without solution annealing before welding or further fabricationHaynes says B-3 is then very susceptible to cracking in the welded region; the crack may not show until the component is in service
Ni4Mo phase formation, loss of ductility and stress corrosion resistancemoderate severityTime in the 500 to 900 °C range; B-3 forms the second phase more slowly than B-2 (several hours near 650 °C, against rapid formation near 750 °C for B-2)Ni4Mo reduces ductility and resistance to stress corrosion cracking; B-3 has a reduced susceptibility, not zero
Rapid corrosion from ferric or cupric saltshigh severityFerric or cupric salts in the process, which can form when hydrochloric acid contacts iron or copperThe brochure says these salts may cause rapid corrosion failure, so the alloy is not recommended with them
Attack by wet chlorine or hypochloritehigh severityWet chlorine gas or hypochlorite bleach in serviceThe alloy does not withstand wet chlorine gas or hypochlorite bleach

Side effects on surrounding parts

Side effects on surrounding parts
AffectsEffect
Alloy cost and supplyMolybdenum is the largest alloying element (nominal 28.5 %), so the alloy's price and supply depend on molybdenum. In 2025 China, Chile, the United States, Peru and Mexico together produced 90 % of world molybdenum.

Handling and storage

  • Solution anneal at 1066 °C (1950 °F), hold 10 to 30 minutes depending on thickness, then water quench; rapid air cooling is feasible for structures thinner than 10 mm.
  • Hot working has a narrow window: the recommended start temperature for hot forging is 1232 °C (2250 °F) and the finish temperature 982 °C (1800 °F).
  • Haynes gives ENiMo-10 (SFA 5.11) coated electrodes and ERNiMo-10 (SFA 5.14) bare rod as matching filler metals, with DIN 2.4696 and 2.4695 equivalents.
  • Oxyacetylene and submerged arc welding are not recommended when the item will be used in corrosive service, and excessive heat input should be avoided.

Mitigations

  • Re-anneal cold-worked parts after outer-fibre elongation of 7 % or more, as Haynes advises for optimum corrosion performance.

Supply and geography

How common the raw materials are and where they come from.

Nickel (mine production, nickel content)

USGS: world nickel resources are more than 350 million tons, and world reserves are more than 140,000,000 metric tons (2025 summary)

Top producers (2025)
Indonesia, Philippines, Russia, Canada, New Caledonia
Recycling
USGS: in 2025 nickel recovered from scrap was about 60 % of apparent consumption, and most recycled nickel went into new alloys and stainless steel.
Substitutes
USGS: titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments.

Molybdenum (mine production, molybdenum content)

Top producers (2025)
China, Chile, United States, Peru, Mexico
Recycling
USGS: molybdenum recycled as part of new and old steel and other scrap may be as much as 30 % of apparent supply.
Substitutes
USGS: there is little substitution for molybdenum in its major application in steels and cast irons.