Hastelloy metals and alloys are known for their superior ability to withstand high temperatures and corrosion. Haynes International first developed these types of superalloys, following the invention of stainless steel in 1913.

Stainless steel and Hastelloy alloys both offer incredible strength and formability under stress, and good ductility. However, Hastelloy alloys resist corrosive chemicals and acids, such as hydrochloric acid, which distinguishes them from other alloys. Additionally, a metallurgist can engineer a superalloy to withstand oxidizing agents.

What are Hastelloy metals and alloys?

Metals, such as silver or copper, are pure elements, whereas alloys are manmade mixtures of two or more elements. Although stainless steel and Hastelloy alloys may be used in similar applications, there are some key differences between these materials.

STAINLESS STEEL AND HASTELLOY ALLOY DIFFERENCES

Nickel and molybdenum are the primary ingredients in any of the Hastelloy alloys. Nickel is a naturally occurring silvery metal with a melting point of 2,651ºF. It is highly resistant to corrosion.

Similarly, molybdenum is a shiny, silvery metal with an incredibly high melting point of 4,752ºF. It’s used to enhance the strength, electrical conductivity, and hardness of certain alloys.

On the other hand, stainless steel is fortified with nickel and chromium. Chromium acts as an agent to prevent rusting. However, the presence of higher percentages of nickel and molybdenum make Hastelloy metals and alloys more resistant to corrosion than stainless steel, especially in elevated temperatures.

HASTELLOY ALLOY OPTIMIZATION

Although all grades of Hastelloy alloys are corrosion resistant, certain grades have been optimized for specific purposes. The mechanical properties of different grades of alloys determines their impact on deep drawing, stamping, and welding processes.

What are the characteristics of Hastelloy B2?

·Great resistance to stress corrosion cracking and pitting

·Significant resistance to reducing conditions like hydrogen chloride, sulfuric, acetic and phosphoric acids

·Resistance to hydrochloric acid at all concentrations and temperatures

Chemical Composition, %

Mechanical Properties