Stress-Oriented Hydrogen Induced Cracking (SOHIC)

Explore this topic

Integripedia
Articles
Videos
Downloads & Resources

« Back to Topics

Overview of Stress-Oriented Hydrogen Induced Cracking (SOHIC)

Stress-Oriented Hydrogen Induced Cracking (SOHIC) is a common, insidious form of wet H2S cracking. SOHIC is a type of cracking that can easily lead to failure and needs to be mitigated. It is made up of a series of HIC (hydrogen induced cracking) cracks that are stacked perpendicularly in the direction of through wall cracks and driven by high residual or applied stresses. It's fairly well known that above 50 ppm of H2S content, below 180F temperature in aqueous sour waters, that our pressure equipment is susceptible to wet H2S cracking. It's also fairly well known that cyanides in overhead systems of cat crackers and cokers can significantly increase susceptibility.

All susceptible systems should be inspected and maintained according to the latest edition of NACE RP0296. Equipment that is susceptible to SOHIC needs to be post weld heat treated (PWHT) or alloyed up. HIC resistant steels and polymeric coatings have been successfully applied, as well as stainless steel clad materials in more aggressive environments.

Topic Tools

Share this Topic

Contribute to Definition

We welcome updates to this Integripedia definition from the Inspectioneering community. Click the link below to submit any recommended changes for Inspectioneering's team of editors to review.

Contribute to Definition

Articles about Stress-Oriented Hydrogen Induced Cracking (SOHIC)

Tri-Lateral Phased Array: A Novel Technique for Identifying Wet H2S Damage

January/February 2022 Inspectioneering Journal

Within one unit, TriLat combines the power of two probes containing three angle beam sets to identify and quantify cracking at early stages. The result is inspection speeds up to ten times faster than traditional AUT systems, depending on probe size.

Authors: Jose Aparicio, Chase David, Roberto Mendoza

Damage Control: Wet H2S Damage Mitigation

January/February 2022 Inspectioneering Journal

This edition of Damage Control will offer practical steps to mitigate different forms of wet H2S damage and help to minimize long-term inspection and maintenance costs related to wet H2S damage.

Authors: Phillip E. Prueter

Damage Control: Wet H2S Damage Assessment

November/December 2021 Inspectioneering Journal

This issue of Damage Control offers a perspective on how to assess the different forms of wet H2S damage using modern FFS and computational analysis techniques with the safe operation of damaged pressure vessels, piping, and associated components.

Authors: Phillip E. Prueter

Damage Control: Wet H2S Damage Detection

September/October 2021 Inspectioneering Journal

This article summarizes the fundamentals of wet H2S-related damage mechanisms, offers some practical inspection guidance, and reviews a notable industry failure caused by different forms of wet H2S damage.

Authors: Phillip E. Prueter

99 Diseases of Pressure Equipment: Wet H2S Cracking (HIC/SOHIC)

November/December 2003 Inspectioneering Journal

There are a variety of forms of wet H2S cracking. In this short article I will focus on two of the most common forms: hydrogen induced cracking and stress-oriented hydrogen induced cracking (HIC/ SOHIC). HIC is often fairly innocuous (but not...

Authors: John Reynolds

Introducing Tri-Lateral Phased Array

Partner Content

Tri-Lateral Phased Array is a novel robotic phased array ultrasonic testing technique for the on-stream inspection of fixed equipment in wet hydrogen sulfide (H2S) service. TriLat identifies and quantifies wet H2S damage in the base metal of...

Wet H2S Cracking in Steel Vessels

May/June 1995 Inspectioneering Journal

Exposure of carbon steel equipment to wet H2S service environments can lead to various forms of attack, e.g. hydrogen blistering and hydrogen induced cracking (HIC), stress oriented hydrogen induced cracking (SOHIC) and sulfide stress cracking...

Authors: Dr. Russell D. Kane, Dr. Michael S. Cayard