The basic performance parameters of Hastelloy alloy C276

With the continuous advancement of science and technology, the application of stainless steel is becoming more and more extensive. However, in some special fields (such as ocean, environmental protection, energy, petrochemical, food, etc.), ordinary stainless steel 304 is no longer competent. In these special fields, special stainless steel is indispensable and irreplaceable.

In recent years, with the rapid development of the economy and the continuous improvement of technology in the industrial field, more and more projects require stainless steel with higher performance, and nickel-based alloy is one of the representative steels. According to performance, nickel-based alloy Fasteners can be divided into: heat-resistant alloys, wear-resistant alloys, corrosion-resistant alloys, precision alloys and shape memory alloys. Today, we mainly learn about Hastelloy C-276 Alloy in corrosion-resistant alloys.

Hastelloy C-276 Alloy Introduction

Hastelloy C-276 Alloy is a Ni-Cr-Mo alloy with excellent corrosion resistance in both oxidizing and reducing environments.

This alloy improves corrosion resistance by reducing the C and Si content and controlling the temperature of the heated part to inhibit the precipitation of carbides in the heat-affected zone. Based on this feature, it is widely used in harsh environments such as chemical industry and petroleum equipment.

Material Grades and Standards

Chemical Composition

Physical properties

Mechanical properties

Pitting resistance   

Crevice corrosion resistance  

Test methods：

1 )ASTM G48 Method c:  Test time 72 hours

2)ASTM G48 Method D:  Test time 72 hours, using multi-tooth clamps to form gaps

3)Green death Solution immersion：The test time is 24 hours, the test solution is 7% H₂SO₄+3% HCl+1% FeCl₃+1% CuCl₂, and the crevice corrosion test uses more

The teeth of the clamp form a gap.

Resistant to intergranular corrosion

Test method: ASTM G28 method A Test conditions: 24 hours

Boiling 50% H2SO₄-Fe₂ (SO₄)₃ aqueous solution.

Acid corrosion resistance

Test conditions: Test time 24 hours Corrosion rate unit:

Can be converted from g/m²·h to mm/y

mm/y=g/m² ·h×8.76/d (d is density)

[d]: NAS NW276:8.90g/cm³,

NAS 254N:8.06g/cm³,

NAS 329J3L:7.80g/cm³,

SUS 316L:7.98g/cm³

Stress corrosion cracking resistance

Test conditions: Soak in boiling MgCl₂ aqueous solution, test time 300 hours, use U-shaped bending specimen

o: Not cracked

                                    x: Stress corrosion cracking

Metallography

C276 is an austenite structure with a face-centered cubic lattice structure.

Welding performance

The same conventional welding methods as for stainless steel can be used. Please use solder of the same metal as the solder. No heat treatment is required after welding.

Heat treatment

The solution treatment temperature is 1150-1170°C, and rapid cooling is required after heat treatment.

Application

C276 alloy has been widely used in the chemical and petrochemical fields, such as in components and catalyst systems that come into contact with chloride-containing organic matter.

This material is particularly suitable for high temperature, inorganic acid and organic acid mixed with impurities (such as formic acid and acetic acid), seawater corrosion environment

use.

(1) Pulp and paper industry, such as digestion and bleaching vessels

(2)Scrubbers, reheaters, wet steam fans, etc. in FGD systems

(3)Equipment and components operating in sour gas environments

(4)Reactors for acetic acid and acidic products

(5)Sulfuric acid condenser

(6)Methylene diphenyl isocyanate (MDI)

(7)Production and processing of impure phosphoric acid

(8)Others: heat exchangers, centrifuges, dryers, reaction tanks, complete salt production equipment, flue gas desulfurization equipment, etc.