2.What is the Hastelloy B2 equivalent to?
UNS Designation: N10665
ISO/International: W.Nr. 2.4617 (German), NiMo28 (EN 2.4617)
Other Industry Standards: ASTM B333 (wrought), ASTM B335 (rod/bar), and ASME SB - 333/SB - 335.
3.What is the ASTM standard for Hastelloy B2?
ASTM B333: Specifies wrought seamless tubes and pipes for general use in corrosive environments.
ASTM B335: Covers wrought bars and rods, including round, square, and hexagonal shapes.
ASTM B334: Applies to welded tubes and pipes, though less common than B333 for critical applications.
4.What are the advantages of Hastelloy B2?
Superior resistance to concentrated hydrochloric acid (even at boiling temperatures) and sulfuric acid, outperforming many stainless steels and other nickel alloys.
Resists pitting, crevice corrosion, and stress - corrosion cracking (SCC) in reducing media.
Maintains mechanical strength up to ~1000°F (540°C), making it suitable for high - temperature chemical processing.
Can be welded using standard techniques (e.g., TIG, MIG) with proper precautions to avoid carbon contamination, which can reduce corrosion resistance.
Formable into complex shapes for components like reactors, heat exchangers, and piping.
Ideal for applications involving hydrogen chloride (HCl) gas, wet HCl solutions, and other chloride - containing reducing agents.
5.What are the advantages of Hastelloy B2?
Poor resistance to oxidizing acids (e.g., nitric acid) or environments with dissolved oxygen, as molybdenum - rich surfaces can oxidize and corrode.
High carbon content (≤0.02%) in the alloy is critical; exposure to carbon during welding or heat treatment can form carbides, leading to grain boundary corrosion (e.g., "sensitization").
Oxygen in the material can reduce ductility and corrosion resistance.
More expensive than stainless steels due to high nickel and molybdenum content, which increases production and material costs.
Limited availability compared to common alloys, requiring specialized suppliers.
Not suitable for applications where both oxidizing and reducing conditions fluctuate, as its performance is optimized for purely reducing media.
Requires solution annealing after welding to restore uniform microstructure and corrosion resistance, adding complexity to fabrication processes.
