Nickel-based super alloy: Hastelloy B3 (UNS N10675)

What is Hastelloy B3?

Hastelloy B3 (UNS N10675/W.Nr. 2.4600/Alloy B3) is a nickel-molybdenum alloy with the addition of chromium, iron and other elements. It has excellent resistance to hydrochloric acid at all concentrations and temperatures. It also has good performance in sulfuric, acetic, formic and phosphoric acids, and other non-oxidizing media. Alloy B3 has excellent resistance to pitting corrosion, stress-corrosion cracking and to knife-line and heat-affected zone attack. Compared to Hastelloy B2, Hastelloy B3 has more superior thermal stability. It’s widely used in chemical processes, vacuum furnaces, and piping components in reducing environments.
Hastelloy B-3 (UNS N10675) is a solid solution strengthened, nickel-molybdenum alloy, typically used in extreme reducing conditions. Hastelloy B-3 has significantly lower carbon, silicon and iron compared to its’ predecessor, Hastelloy B (UNS N10001), making the alloy less susceptible to decreased corrosion resistance in the weld zone, in the as-welded condition. Controlling other alloying elements such as iron and chromium solved other issues concerning fabricability. Hastelloy B3 (n10675) is a nickel base superalloy composed of nickel, molybdenum, cobalt and other elements. The nickel content of Hastelloy B3 is about 65%. Hastelloy B3 (n10675) nickel base alloy is a new material based on Hastelloy B2, which improves the thermal stability and corrosion resistance of the material, and improves the hot forming and cold forming properties. In recent years, it has been more and more used in the production and manufacturing of chemical equipment.

Characteristics of Hastelloy B3 (UNS N10675)

  • 1. Control of iron and chromium elements at the lowest levels, and prevent Beta phase Ni4Mo generated.
  • 2. Excellent corrosion resistance to reductive environment.
  • 3. Excellent resistance to corrosive medium concentration sulfuric acid and many non oxidizing acids.
  • 4. Good resistance to chloride ion reduction stress corrosion cracking (SCC).
  • 5. Excellent resistance to all kinds of organic acid corrosions. Hastelloy B-3 alloy is a new member of nickel molybdenum alloys has excellent corrosion resistance to hydrochloric acid at all temperature and the concentration . At the same time it also has good corrosion resistance to sulfuric acid, acetic acid, formic acid, phosphoric acid and other oxidizing medium. Because of its chemical composition adjustment, its thermal stability compared to the original Hastelloy B-2 alloy has improved significantly. Hastelloy B-3 alloy has high resistance to pitting corrosion, stress corrosion cracking, knife-line and heat-affected zone attacks,and etc.
  • 6. Thermal stability superior to alloy B-2: compared to Hastelloy B-2, the biggest advantage of Hastelloy B-3 is maintaining excellent ductility during transient exposures to intermediate temperatures. The exposures regularly occur in the process of heat treatment processing. When a short exposure to the temperature of 700℃, B-2 alloy is very easy embrittlement, while B-3 alloy showed significant embrittlement resistance, and can make the show for a few hours. This provides a great convenience for the alloy provided in the form of complex, such as forming device components.

20200902224436 49046 - Nickel-based super alloy: Hastelloy B3 (UNS N10675)

Hastelloy B3 Forged Elbow 1″ 3000#

Types of Hastelloy

  • Hastelloy B-3 nickel molybdenum alloy has excellent corrosion resistance in reducing environment
  • The upgraded version of Hastelloy B-3: B-3 has excellent corrosion resistance to hydrochloric acid at any temperature and concentration
  • Hastelloy C-4: good thermal stability, good toughness and corrosion resistance at 650-1040 ℃
  • Hastelloy C-22: has better uniform corrosion resistance than C-4 and C-276 in oxidizing medium and excellent local corrosion resistance
  • Hastelloy C-276: good resistance to oxidizing and moderate reducing corrosion, excellent resistance to stress corrosion
  • Hastelloy C-2000: the most comprehensive corrosion resistant alloy with excellent uniform corrosion resistance in oxidation and reduction environments
  • Hastelloy G-35: the upgraded product of G-30 has better corrosion resistance and thermal stability, and has excellent performance in phosphoric acid and other strong oxidizing mixed acid media with high chromium content
  • Hastelloy X: combined with the characteristics of high strength, oxidation resistance and easy processing, each of the above grades has its own specific chemical composition, mechanical properties and strong points, so we can’t generalize the characteristics of Hastelloy.

Hastelloy alloy is mainly divided into three series B, C and G. it is mainly used in iron-based Cr Ni or Cr Ni Mo stainless steel, non-metallic materials and other occasions with strong corrosive medium.
In order to improve the corrosion resistance and cold and hot working properties of Hastelloy, three major improvements have been made to Hastelloy:

  • Series B: B → B-3 (00ni70mo28) → B-3
  • Series C: C → C-276 (00cr16mo16w4) → C-4 (00cr16mo16) → C-22 (00cr22mo13w3) → C-2000 (00cr20mo16)
  • G Series: G → G-3 (00cr22ni48mo7cu) → G-30 (00cr30ni48mo7cu)
  • The most widely used materials are N10675 (B-3), N10276 (C-276), N06022 (C-22), N06455 (C-4) and N06985 (G-3)

Chemical Composition of Hastelloy B3 (UNS N10675)

C≤ Si≤ Mn≤ P≤ S≤ Cr≥ Ni≥ Mo≥ Cu≤
0.01 0.10 3.00 0.030 0.010 1.00-3.00 65.0 27.0-32.0 0.20
Nb/Ta≤ Al≤ Ti≤ Fe≤ Co≤ V≤ W≤ Ni+Mo Ta≤
0.20 0.50 0.20 1.00-3.00 3.00 0.20 3.00 94.0-98.0 0.20

Equivalent Grades of Hastelloy B3 (UNS N10675)

Hastelloy B-3 NS3203 Hastelloy B-3 N10675 NiMo29Cr 2.46

Physical Properties of Hastelloy B3 (UNS N10675)


Melting Point

Electric resistivity 

Coefficient of thermal expansion 

Elastic modulus

Hardness (Brinell)/HB

Operating temperature
(°C )







 -200 – +400

Mechanical Properties of Hastelloy B3 (UNS N10675)


  • Heat Treatment: 2100°F (1150°C)
  • Tensile Strength: 110 ksi (760 MPa) min 125 ksi (860 MPa) typ
  • Suggested Operating Conditions: -300°F to 1800°F (-184°C to 900°C)

Product Forms and Standards of Hastelloy B3

Product Form Standard
Sheet, Plate & Strip ASTM B333
Billet, Rod & Bar ASTM B335, B472
Coated Electrodes DIN 2.4696
Bare Welding Rods & Wire DIN 2.4695
Seamless Pipe & Tube ASTM B622
Welded Pipe & Tube ASTM B619, B626
Fittings ASTM B366, B462
Forgings ASTM B564, B462

Forming processing of Hastelloy B3 (UNS N10675)

  • (1) The elongation of Hastelloy B3 is higher, which creates favorable conditions for cold forming.
  • (2) Hastelloy B3 is harder than austenitic stainless steel and has more obvious work hardening tendency, so it needs more pressure or step-by-step forming in cold forming.
  • (3) When the cold forming deformation rate of Hastelloy B3 is less than 10%, the corrosion resistance of the machined parts will not be affected, but the existence of residual stress may cause hot cracks in the weld. Therefore, the influence of residual stress should be eliminated as much as possible for the workpiece to be welded in the later stage.
  • (4) Cold forming with severe deformation can improve the yield ratio of Hastelloy B3, and increase the sensitivity of stress corrosion and crack. Intermediate and final heat treatment processes are often used.
  • (5) Hastelloy B3 is very sensitive to oxidizing medium, sulfur, phosphorus, lead and other low melting point metals at high temperature.
  • (6) In the temperature range of 600-800 ℃ and too long heating time, brittle phase will be produced in Hastelloy B3 alloy, which will lead to the decrease of elongation. Moreover, hot cracking is easy to occur in this temperature range when the external force or deformation is limited. Therefore, the temperature must be controlled above 900 ℃.
  • (7) Before the processing and pressing of Hastelloy B3 material, the mold surface contacting with the workpiece shall be cleaned; during cold working, lubrication method can be adopted, and degreasing treatment or alkali cleaning shall be carried out immediately after forming.
  • (8) After the workpiece is discharged from the furnace and cooled, the oxide film on the surface is relatively thick, which should be fully acid washed. If there is residual oxide film, cracks may occur during the next pressing; if necessary, sandblasting can be carried out before pickling.

Welding of Hastelloy B3 (UNS N10675)

  • (1) Before the forming process, if the raw blank needs to splice the weld, it is better to choose the GTAW welding method, so as to better protect the weld from oxidation. If manual arc welding method is adopted, it is easy to cause the intermediate weld bead to be oxidized. Even if each layer is polished and cleaned, it is difficult to ensure the thorough cleaning, and there is a small residual oxide layer, which may also form the weld Processing performance is affected. Before welding, the attachment and oxide layer on groove and base metal surface must be removed, because the existence of oxide film and impurities will affect the performance of weld and HAZ. It is better to use small current to avoid too slow speed and swing. The interlayer temperature should be controlled below 100 ℃. The front and back sides should be protected by argon to avoid high temperature oxidation and burning of alloy elements. Before pressing, the weld surface shall be polished smooth, and the thick oxide layer on the weld surface shall be removed and acid pickling shall be supplemented. Because the oxide layer of Hastelloy B3 weld is very hard, it is difficult to remove it by direct acid pickling. It is easy to produce fine cracks in the process of pressing forming, which will affect the performance of weld.
  • (2) The advantage of hot forming is that it can be formed at one time and can avoid work hardening. If the forming temperature can be controlled well, heat treatment can be avoided. However, the temperature changes greatly in the hot forming process, and each region is different, and even the surface directly contacting with the die may be far lower than the temperature inside the metal, which is difficult to measure and control. Once the local material enters the sensitive temperature region during the processing, the micro cracks and other defects will be difficult to eliminate in the later solution heat treatment. The cold forming process was selected based on the experience of the processing plant. Molding is preferred for pressing method. When spinning must be adopted, cold spinning or warm spinning with temperature no more than 400 ℃ shall be adopted.
  • (3) In the cold forming process, the step-by-step forming process should be adopted when the deformation rate is large. The intermediate heat treatment should be carried out for the step forming, and the solution heat treatment should be selected, and the temperature should be controlled above 1000 ℃. The solution heat treatment process was selected and the temperature was 1060 ~ 1080 ℃. After the final pressing of the workpiece, a solution heat treatment should be carried out to eliminate the residual stress and avoid affecting the subsequent welding quality.

Heat treatment of Hastelloy B3 (UNS N10675)

It is very important to keep the workpiece clean and pollution-free before and during heat treatment of Hastelloy B3 (n10675) Hastelloy alloy. In the heating process, the workpiece should not contact with sulfur, phosphorus, lead and other low melting point metals, otherwise the properties of the alloy will be damaged and the alloy will become brittle. The heating furnace should be electric furnace. If gas or oil fired furnace is used, the lower the sulfur content in the fuel, the better. According to the recommendation of material manufacturers, the total sulfur content in natural gas and liquefied petroleum gas is not more than 0.1% (V), the sulfur content in city gas is not more than 0.25 g / m3, and the sulfur content in fuel oil should be less than 0.5% (W).
The furnace gas must be clean and suitable for micro reduction. The fluctuation between oxidizability and reducibility of furnace gas should be avoided, and the heating flame cannot directly contact the workpiece. Before entering the furnace, the workpiece must be protected from high temperature deformation. The heating speed of the workpiece should be as fast as possible, and the workpiece can not be put into the furnace until the furnace temperature reaches the heat treatment temperature. After being discharged from the furnace, the water should be cooled quickly, and the immersion method or the whole area should be sprayed evenly. It is strictly forbidden to use water pipes for pouring, so as to prevent abnormal deformation or tearing due to uneven cooling and heating.

Application areas of nickel-based alloy Hastelloy B3 (UNS N10675):

20200902225659 70005 - Nickel-based super alloy: Hastelloy B3 (UNS N10675)

An Alloy B3 90DEG Elbow 6″ SCH80S extruded from the UNS N10675 seamless pipe.

Hastelloy B3 (UNS N10675) is widely used in the chemical, petrochemical, energy manufacturing and pollution control related processing and equipment , especially in the processes dealing with various acids (sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid and so on. Some of the more common uses of Hastelloy B3 include:

  • Wire wound resistors.
  • Bimetal contacts.
  • Electric and electronic applications.
  • Marine engineering.
  • Chemical and hydrocarbon processing equipment.
  • Gasoline and freshwater tanks.
  • Crude petroleum stills.
  • De-aerating heaters.
  • Boiler feed water heaters and other heat exchangers.
  • Pumps, shafts and fasteners.
  • Industrial heat exchangers.
  • Chlorinated solvents.
  • Crude oil distillation towers.
  • Meter and valve parts.
  • Screw machine products.
  • Oil refinery piping.
  • Heat exchangers.
  • Nuclear fuel production.
  • Generator tubing.
  • High temperature heating coils.
  • Crude oil transfer piping.
  • Propeller and pump shafts.
  • Piping system.
  • Heat exchange tubes.
  • Pipe fittings.
  • Flanges.
  • Valves.

Variety specifications and supply status of Nickel-based super alloy: Hastelloy B3 (UNS N10675):

Variety classification:

Yaang Pipe Industry can produce various specifications of Hastelloy B3 seamless pipeHastelloy B3 steel plateHastelloy B3 round bar, Hastelloy B3 forgings, Hastelloy B3 flangeHastelloy B3 pipe fittings, Hastelloy B3 welded pipe, Hastelloy B3 steel strip, Hastelloy B3 wire and supporting welding materials. 

Delivery status:

  • Seamless pipe: solid solution + acid white, length can be set;
  • Plate: solid solution, pickling, trimming;
  • Welded pipe: solid solution acid white + RT% flaw detection;
  • Forging: annealing + car polish; Bars are forged and rolled, surface polished or car polished;
  • Strips are delivered after cold rolling, solid solution soft state, and deoxidized;
  • Wire rods are finely ground in solid solution pickled disk or straight strips, solid solution straight strips Delivery in light state.

Source: China Hastelloy B3 Flanges Manufcturer – Yaang Pipe Industry (

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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Nickel-based super alloy: Hastelloy B3 (UNS N10675)
Hastelloy B3 (UNS N10675/W.Nr. 2.4600/Alloy B3) is a nickel-molybdenum alloy with the addition of chromium, iron and other elements.
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