Overview

Hastelloy B2 is a nickel-molybdenum alloy with significant resistance to reducing environments, such as hydrogen chloride gas and sulfuric, acetic and phosphoric acids. Hastelloy B2 provides resistance to pure sulfuric acid and a number of non-oxidizing acids. The alloy should not be used in oxidizing media or where oxidizing contaminants are available in reducing media. Premature failure may occur if alloy B2 is used where iron or copper is present in a system containing hydrochloric acid.

Industry users like the resistance to a wide range of organic acids and the resistance to chloride-induced stress-corrosion cracking.

Hastelloy B2 resists the formation of grain boundary carbide precipitates in the weld heat-affected zone, making it suitable for most chemical process applications in the as-welded condition. The heat-affected weld zones have reduced precipitation of carbides and other phases to ensure uniform corrosion resistance.
Alloy B2 also has excellent resistance to pitting and stress corrosion cracking.

Applications

Superior resistance to hydrochloric acid, aluminum chloride catalysts and other strongly reducing chemicals. Excellent high-temperature strength in inert and vacuum atmospheres.

Hastelloy B2 is a nickel-molybdenum alloy particularly suited for equipment handling reducing chemical environments .

Applications in the chemical process industry involving sulfuric, phosphoric, hydrochloric and acetic acid. Temperature uses vary from ambient temperature to 1500°F depending on the environments (please call for technical advice).

Chemistry

Tensile Data

Specifications

Formability
Hastelloy B2 does work harden, but can be formed when the proper precautions are taken. Sheet (0.063" thick) in the heat treated condition at 1950°F and rapid quenched has an average olsen cup depth of 0.57" or 14.5mm.

Welding
Hastelloy B2 resists the formation of grain boundary carbide precipitates in the weld heat-affected zone, making it suitable for most chemical process applications in the as-welded condition. The heat-affected weld zones have reduced precipitation of carbides and other phases to ensure uniform corrosion resistance.

Machining

Machinability Ratings

Nickel & cobalt base corrosion, temperature and wear-resistant alloys, such as Hastelloy B2, are classified as moderate to difficult when machining, however, it should be emphasized that these alloys can be machined using conventional production methods at satisfactory rates. During machining these alloys work harden rapidly, generate high heat during cutting, weld to the cutting tool surface and offer high resistance to metal removal because of their high shear strengths. The following are key points which should be considered during machining operations:

CAPACITY - Machine should be rigid and overpowered as much as possible.
RIGIDITY - Work piece and tool should be held rigid. Minimize tool overhang.
TOOL SHARPNESS - Make sure tools are sharp at all times. Change to sharpened tools at regular intervals rather than out of necessity. A 0.015 inch wear land is considered a dull tool.
TOOLS - Use positive rake angle tools for most machining operations. Negative rake angle tools can be considered for intermittent cuts and heavy stock removal. Carbide-tipped tools are suggested for most applications. High speed tools can be used, with lower production rates, and are often recommended for intermittent cuts.
POSITIVE CUTS - Use heavy, constant, feeds to maintain positive cutting action. If feed slows and the tool dwells in the cut, work hardening occurs, tool life deteriorates and close tolerances are impossible.
LUBRICATION - lubricants are desirable, soluble oils are recommended especially when using carbide tooling. Detailed machining parameters are presented Tables 16 and17. General plasma cutting recommendations are presented in Table 18.