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Different Types of Corrosion
- Recognition, Mechanisms & Prevention

Hydrogen-Induced Cracking

Recognition of Hydrogen-Induced Cracking (HIC)

What is hydrogen-induced cracking?

Hydrogen-Induced Cracking (HIC) is the stepwise internal cracks that connect adjacent hydrogen blisters on different planes in the metal, or to the metal surface. It is also known as stepwise cracking.

HIC is especially prevalent in iron alloys because of the restricted slip capabilities in the predominantly body-centered cubic (BCC) structure. HIC is generally limited to steels having a hardness of 22 or greater on the Rockwell C scale.

Mechanisms of Hydrogen-Induced Cracking (HIC)

What causes hydrogen-induced cracking?

Hydrogen-induced cracking results from atomic hydrogen being absorbed by solid metals. This can occur during elevated-temperature thermal treatments and in service during electroplating, contact with maintenance chemicals, wet H₂S, corrosion reactions, cathodic protection, and operating in high-pressure hydrogen-containing environments.

Modeling, Prediction, and Prevention of Hydrogen-Induced Cracking (HIC)

How to select alloy steels for resistance to hydrogen-induced cracking?
How to calculate atomic hydrogen concentration in steels?
How to calculate internal hydrogen gas pressure in steels?
How to determine if post-weld heat treatment (PWHT) or pre-heating is required?
How to assess the susceptibility of an alloy steel to low temperature hydrogen damages such as hydrogen blistering (HB), hydrogen-induced cracking (HIC), stress-oriented hydrogen-induced cracking (SOHIC), stepwise cracking (SWC), hydrogen embrittlement (HE), hydrogen stress cracking (HSC), sulfide stress cracking (SSC), and soft zone cracking (SZC)?

H2Compass is a powerful software for modeling and prediction of low temperature hydrogen damages and high temperature hydrogen attack (HTHA). H2Compass software provides instant answers to the above questions. The software can be used to determine the atomic hydrogen concentration in steels, the internal hydrogen gas pressure at hydrogen traps in steels, the steel's susceptibility to low temperature hydrogen damages, and the requirements for post-weld heat treatment (PWHT) and pre-heating.

How to prevent hydrogen-induced cracking? Hydrogen-induced cracking can be prevented through:

• Control of stress level (residual or load) and hardness. Computer software H2Compass can be used to determine when PWHT or Pre-Heating is required. Click here for details on the H2Compass software.

• Avoid the hydrogen source.

• Baking to remove hydrogen.

For more details on Hydrogen-Induced Cracking (HIC)

Where can I learn more about hydrogen-induced cracking? More details on hydrogen-induced cracking are included in the following corrosion courses which you can take as in-house training courses, course-on-demand, online courses or distance learning courses:

Corrosion and Its Prevention (5 days)
Environmental Cracking (HB-HIC-SWC-SOHIC-SSC-SZC-HSC-HE-SCC): Recognition, Mechanisms and Prevention (5days)
API 571 Damage Mechanisms Affecting Fixed Equipment in the Refining and Petrochemical Industries (5 days)
Corrosion, Metallurgy, Failure Analysis and Prevention (5 days)
Marine Corrosion, Causes and Prevention (2 days)
Materials Selection and Corrosion (5 days)
Stainless Steels and Alloys: Why They Resist Corrosion and How They Fail (2 days)

If you require corrosion expert witness or corrosion consulting service on hydrogen induced cracking, our NACE certified Corrosion Specialist is able to help. Contact us for a quote.

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