Hastelloy b-2 alloy material

What is Hastelloy b-2 alloy material？

Hastelloy Material (Hastelloy alloy) is the United States of America Hastelloy International Corporation produced by the nickel-based corrosion-resistant Alloy Steel of the commercial grade of the collective name. Including nickel-molybdenum Hastelloy (Hastelloy) B-2, nickel-chromium-molybdenum Hastelloy (Hastelloy) C-4 and so on.
Hastelloy grades include the following grades:
HASTELLOY B-2 A nickel-molybdenum alloy with excellent corrosion resistance in reducing environments HASTELLOY B-3 An upgraded version of B-2 with excellent corrosion resistance to hydrochloric acid at any temperature and concentration.
HASTELLOY C-4 Better thermal stability, good toughness and corrosion resistance at 650-1040 degrees Celsius.
HASTELLOY C-22 Better uniform corrosion resistance than C-4 and C-276 in oxidizing media, excellent resistance to localized corrosion HASTELLOY C-276 Good resistance to oxidizing and moderate reducing corrosion, excellent resistance to stress corrosion HASTELLOY C-2000 The most comprehensive performance of corrosion-resistant alloys in oxidizing and reducing environments have excellent resistance to uniform corrosion. 

HASTELLOY C-2000 the most versatile corrosion resistant alloy with excellent resistance to uniform corrosion in both oxidizing and reducing environments.

Hastelloy B-2 alloy properties are as follows:
I. Corrosion resistance
Hastelloy B-2 alloy is a very low carbon and silicon content of Ni-Mo alloy, which reduces the precipitation of carbides and other phases in the weld and heat-affected zone, thus ensuring that even in the welded state also has good corrosion resistance. Hastelloy B-2 alloys are known to have excellent corrosion resistance in a variety of reducing media and are resistant to hydrochloric acid at any temperature and any concentration at atmospheric pressure. In the non-gas medium concentration of non-oxidizing sulfuric acid, various concentrations of phosphoric acid, high-temperature acetic acid, formic acid and other organic acids, bromic acid, as well as hydrogen chloride gas have excellent corrosion resistance, at the same time, it is also resistant to halogenated catalysts corrosion. Therefore, Hastelloy B-2 alloy is usually used in a variety of harsh petroleum, chemical processes, such as hydrochloric acid distillation, concentration; ethylbenzene alkylation and low-pressure carbonyl synthesis of acetic acid and other production processes. However, in the Hastelloy B-2 alloy many years of industrial applications found:
(1) Hastelloy B-2 alloy there is a considerable impact on the performance of intergranular corrosion resistance of the two sensitized zone:1200 ~1300 ℃ high-temperature zone and 550 ~900 ℃ of the medium-temperature zone;
(2) Hastelloy B-2 alloy weld metal and heat-affected zone due to dendritic segregation, intermetallic phases and carbides precipitated along the grain boundaries, making it more sensitive to intergranular corrosion;
(3) Hastelloy B-2 alloy has poor thermal stability at medium temperature. When the iron content in the Hastelloy B-2 alloy is reduced to less than 2%, the alloy is sensitive to the transformation of the β-phase (i.e. Ni4Mo phase, an ordered intermetallic compound). When the alloy stays in the temperature range of 650~750 ℃ for a little longer, the β phase is generated instantly. the existence of the β phase reduces the toughness of the Hastelloy B-2 alloy, making it sensitive to stress corrosion, and even causes the Hastelloy B-2 alloy to crack in the production of raw materials (e.g., in the process of hot rolling), in the process of equipment manufacturing (e.g., in the overall heat treatment of the Hastelloy B-2 alloy equipment after welding), and in the Hastelloy B-2 alloy equipment in the service environment. Cracking. Nowadays, China and the world's designated standard test methods for Hastelloy B-2 alloy resistance to intergranular corrosion performance are atmospheric pressure boiling hydrochloric acid method, evaluation method for weight loss method. As Hastelloy B-2 alloy is a hydrochloric acid corrosion-resistant alloy, the atmospheric pressure boiling hydrochloric acid method to test the intergranular corrosion tendency of Hastelloy B-2 alloy is quite insensitive. Domestic research institutions with high-temperature hydrochloric acid method of Hastelloy B-2 alloy research found that: Hastelloy B-2 alloy corrosion resistance not only depends on its chemical composition, but also depends on the control process of its hot processing. When the hot working process is not controlled, Hashi B-2 alloy not only grain growth, and intergranular will precipitate high Mo σ phase, at this time, Hashi B-2 alloy resistance to intergranular corrosion of the performance of a significant decline in high-temperature hydrochloric acid test, the coarse grain plate and the normal plate of the depth of corrosion of the grain boundaries of the difference between the depth of about twice as much.

2.Physical Properties
The physical properties of Hastelloy B-2 alloy are shown in the table below. Density:9.2g/cm3, Melting point:1330~1380℃, Magnetic permeability:(℃, RT)≤1.001