Hastelloy B-2 Alloy Introduction to Characteristics and Execution Standards

Hastelloy B-2 Alloy Introduction to Characteristics and Execution Standards

Common Trade Names: Hastelloy B2, Alloy B2; Nimofer 6928;

Alloy B2 (UNS N10665 / W.Nr. 2.4617) is a solid solution strengthened, nickel-molybdenum alloy, typically used in extreme reducing conditions. B2 has significantly lower carbon, silicon and iron compared to its’ predecessor, Alloy 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. Stringent chemistry control along with years of development has resulted in the alloy used today, both in Alloy B2 and Alloy B-3 Today, Alloy B2 with restricted chemistry can be used in the welded condition and is less susceptible to SCC under many conditions. As always, care must taken in selecting the right alloy for the desired application.

Alloy B2 should not be used at temperatures between 1000°F and 1600°F as the alloy forms secondary phases that could decrease the ductility of the material.

Available Product Forms: Plate, Sheet, Bar, Pipe;

Specifications Hastelloy B-2 is covered by the following specifications:UNS N10665;

Plate, Sheet, Strip: ASTM B333, ASME SB333,

Bar: ASTM B 335, ASME SB335, (DUAL CERTIFIED TO ASTM B564, ASME SB564 ON 3-1/2 DIA. AND UP);

Welded Pipe: ASTM B619, ASME SB619, CLASS I or II, (ABOVE 8 SCH 40)  ASTM B775, ASME SB775,

Seamless Pipe: ASTM B622, ASME SB622.

Hastelloy B-2 Alloy Chemical Composition

Limiting Chemical Composition, % 

Ni................ Balance 

Cr................1.00 Max.

Mo............. 26.0 to 30.0 

Mn..............1.00 Max.

Fe............... 2.00 Max. 

Si.................0.10 Max.

C................ 0.02 Max. 

P..................0.040 Max.

Co.............. 1.00 Max. 

S..................0.030 Max.