Hastelloy alloy special material properties and introduction
Hastelloy alloy
I. Introduction
Hastelloy is a type of nickel-based alloy. It is currently divided into three series: B, C, and G. It is mainly used for strong corrosion that cannot be used in iron-based Cr-Ni or Cr-Ni-Mo stainless steel, non-metallic materials, etc. It has been widely used in petroleum, chemical industry, environmental protection and many other fields abroad.
In order to improve the corrosion resistance and cold and hot working properties of Hastelloy, Hastelloy has made three major improvements. The development process is as follows:
B series: B → B-2(00Ni70Mo28) → B-3
C series: C → C-276(00Cr16Mo16W4) → C-4(00Cr16Mo16) → C-22 (00Cr22Mo13W3) → C-2000(00Cr20Mo16)
G series: G → G-3 (00Cr22Ni48Mo7Cu) → G-30 (00Cr30Ni48Mo7Cu)
The most widely used materials at present are N10665 (B-2), N10276 (C-276), N06022 (C-22), N06455 (C-4) and N06985 (G-3). The third generation materials N10675 (B-3), N10629 (B-4), and N06059 (C-59) are in the promotion stage. Due to the advancement of metallurgical technology, multiple brands of so-called "super stainless steel" containing ~6% Mo have appeared in recent years, replacing G series alloys, causing a rapid decline in the production and use of G series alloys.
2. Mechanical properties
The mechanical properties of Hastelloy are very outstanding. It has the characteristics of high strength and high toughness, so it is difficult to machine. Moreover, its strain hardening tendency is extremely strong. When the deformation rate reaches 15%, it is about 18-8 Twice that of stainless steel. Hastelloy also has a medium-temperature sensitization zone, and its sensitization tendency increases with the increase in deformation rate. When the temperature is high, Hastelloy easily absorbs harmful elements, causing its mechanical properties and corrosion resistance to decrease.
