HASTELLOY C276

Hastelloy C276 is a nickel-molybdenum-chromium superalloy with an addition of tungsten designed to have excellent corrosion resistance in a wide range of severe environments. The high nickel and molybdenum contents make the nickel steel alloy especially resistant to pitting and crevice corrosion in reducing environments while chromium conveys resistance to oxidizing media. The low carbon content minimizes carbide precipitation during welding to maintain corrosion resistance in as-welded structures. This nickel alloy is resistant to the formation of grain boundary precipitates in the weld heat-affected zone, thus making it suitable for most chemical process application in an as welded condition.

Although there are several variations of the Hastelloy nickel alloy, Hastelloy C-276 is by far the most widely used.

Alloy C-276 is widely used in the most severe environments such as chemical processing, pollution control, pulp and paper production, industrial and municipal waste treatment, and recovery of sour natural gas.

Corrosion Resistant Hastelloy C276

Considered one of the most versatile corrosion resistant alloys available, Hastelloy C-276 exhibits excellent resistance in a wide variety of chemical process environments including those with ferric and cupric chlorides, hot contaminated organic and inorganic media, chlorine, formic and acetic acids, acetic anhydride, seawater, brine and hypochlorite and chlorine dioxide solutions. In addition, alloy C-276 resists formation of grain boundary precipitates in the weld heat affected zone making it useful for most chemical processes in the as-welded condition. This alloy has excellent resistance to pitting and stress corrosion cracking.

The characteristics of Hastelloy C276

• Excellent corrosion resistance in reducing environments
• Exceptional resistance to strong solutions of oxidizing salts, such as ferric and cupric chlorides
• High nickel and molybdenum contents providing good corrosion resistance in reducing environments
• Low carbon content which minimizes grain-boundary carbide precipitation during welding to maintain resistance to corrosion in heat-affected zones of welded joints
• Resistance to localized corrosion such as pitting and stress-corrosion cracking
• One of few materials to withstand the corrosive effects of wet chlorine gas, hypochlorite and chlorine dioxide.

Hastelloy C276 Round Bar is a nickel-iron- chromium alloy with titanium, copper, and molybdenum. Hastelloy C276 Round Bar composition provides great resistance to many corrosive environments, such as pitting, crevice corrosion, intergranular corrosion, and stress- corrosion cracking. Hastelloy C276 has good mechanical properties from moderately to high temperatures. The hot- working range for Hastelloy C276 Round Bar is 1600 to 2150º F. The material has good weldability by all conventional processes.

Chemistry

Characteristic as below

1.Excellent corrosion resistance to most of corrosion media in oxidation and reduction environments.

2.Excellent resist pitting, crevice corrosion and stress corrosion cracking performance.

Hastelloy C-276 Corrosion resistance

C276 alloy suit for many kinds of chemical process industry which contain the oxidizing medium and reductant. High molybdenum and chromium content make it can resist the chloride corrosion, and tungsten make it corrosion resistance better.C276 is one of a few material that can resist the corrosion of most chlorine, hypochlorite and chlorine dioxide, this alloy have prominent corrosion resistance to high concentration chlorate( iron chloride and copper chloride).

Hastelloy C-276 Application field  

C276 is widely used in the chemical field and petrifaction field, such as the element of chloride organic and catalyze system.This material especially suit for high temperature environment, impure inorganic acid and organic acid (such as formic acid and acetic acid), sea-water corrosion environment.

Hastelloy C-276 Other application field  

1. The digester and bleacher in the use of paper pulp and paper making industry.

2.Absorption tower, re-heater and fan in the FGD system.

3. The equipment and parts in the use of acidic gas environments.

4. Acetic acid and anhydride reaction generator

5. Sulfur acid cooling

6.MDI

7.Manufacture and processing of impure phosphoric acid.

Machining

Nickel & cobalt base corrosion, temperature and wear-resistant alloys, such as Hastelloy C276, are classified as moderate to difficult when machining, however, it should be emphasized that these alloys can be machined using conventional production methods at satisfactory rates. During machining these alloys work harden rapidly, generate high heat during cutting, weld to the cutting tool surface and offer high resistance to metal removal because of their high shear strengths. The following are key points which should be considered during machining operations:

CAPACITY - Machine should be rigid and overpowered as much as possible.

RIGIDITY - Work piece and tool should be held rigid. Minimize tool overhang.

•  Excellent performance
•  Low maintenance
•  Reasonable price
•  Ease of fabrication