Inspectioneering
Explore this topic
Overview of Cracking

Cracking is the the physical response in a material or piece of equipment to excessive exposure to damaging conditions. Cracking is usually caused by stress, although it can be exacerbated by other factors. It should go without saying, that you do not want cracking in your equipment.

There are several different types of cracking that affect fixed equipment in the processing industries. These include, but are not limited to:

These and other damage mechanisms are covered in greater detail in API RP 571 - Damage Mechanisms Affecting Fixed Equipment in the Refining Industry.

 

Is this definition incomplete? You can help by contributing to it.

Share this Topic

Related Topics

Amine Cracking Ammonia Stress Corrosion Cracking Brittle Fracture Carburization Caustic Cracking Cavitation Chloride Stress Corrosion Cracking Cooling Water Corrosion Corrosion Fatigue Corrosion Under Insulation (CUI) Decarburization Embrittlement Erosion Corrosion Fatigue (Material) Graphitization High Temperature Hydrogen Attack (HTHA) Hydrochloric Acid Corrosion Hydrofluoric Acid (HFA) Corrosion Hydrogen Assisted Cracking Hydrogen Blistering Hydrogen Embrittlement Hydrogen Induced Cracking (HIC) Hydrogen Stress Cracking Hydrogen Sulfide (H2S) Corrosion Microbiologically Induced Corrosion (MIC) Naphthenic Acid Corrosion (NAC) Phosphoric Acid Corrosion Polythionic Acid Stress Corrosion Cracking (PASCC) Spheroidization Stress Assisted Corrosion Stress Corrosion Cracking (SCC) Stress-Oriented Hydrogen Induced Cracking (SOHIC) Sulfidation Corrosion Sulfuric Acid Corrosion Temper Embrittlement Thermal Fatigue Vibration Fatigue Wet H2S Cracking
Articles about Cracking
  • January/February 2016 Inspectioneering Journal
    By Greg Alvarado at Inspectioneering Journal

    The enormous decline in oil prices over the past 14 months has definitely slowed projects and changed the energy and production landscape. Despite this, refineries, petrochemical plants, and chemical facilities must continue to run safely, responsibly, and reliably.

  • Blog
    May 18, 2015

    This post is based on an article from the September/October 2008 issue of Inspectioneering Journal by Richard Green at Accurate Metallurgical Services. You can find the original article here.

  • November/December 2013 Inspectioneering Journal
    By Tyler Alvarado at Inspectioneering

    Inspectioneering recently had the privilege of speaking with Tom Wanzeck, Vice President of Integrity Services with Willbros Group, Inc. Tom spent more than 20 years managing assets on the owner-operator side before making the leap to the service industry, in which he now manages and facilitates world-class asset and pipeline integrity management programs for clients.

  • January/February 2013 Inspectioneering Journal
    By Ana Benz at IRISNDT

    In this article you will find the failure investigations of six 0.094 inch thick carbon steel vessels. These vessels were in service in natural gas well facilities; some functioned as dryers and were subjected to cyclic loads. Metallographic tests, hardness tests, and fracture surface scanning electron microscopy (SEM) examination results are presented for each of the vessels.

  • September/October 2005 Inspectioneering Journal
    By John Reynolds at Intertek

    Metals will slowly deform under stress and higher temperatures by the mechanism known as creep. The amount of creep deformation that will be experienced is highly dependent upon the level of stress, level of temperature and material properties. It is vital that any component operating in the creep range have Integrity Operating Windows (IOW’s) established where upon operators are required to make adjustments if certain temperatures are reached.

  • Partner Content

    LOTIS utilizes laser profilometry to conduct internal steam reformer tube inspections. The data captured by LOTIS is exceptionally powerful when combined with our LifeQuest™ remaining life assessment capabilities, providing an integrated solution set for the process and syngas industries.

  • July/August 2005 Inspectioneering Journal
    By Mark Bagnell at Equipment Management & Inspection

    Aging phenolic resin reactors built in the 1960's were constructed of SA304 stainless steel, many of which were originally fabricated to ASME Section VIII standards were never registered as such nor with the National Board. Some of these reactors have been exhibiting stress corrosion cracking, (SCC) in the shell plate where external carbon steel structural components such as support legs and vacuum rings are attached. The problem is observed primarily at the interface of support legs where reinforcing pads or "poison" pads have not been installed. Of the vessels inspected to date approximately 50% have been identified as having SCC.

  • January/February 2005 Inspectioneering Journal
    By John Reynolds at Intertek

    Amine cracking is a form of stress corrosion cracking, which is related to alkaline and carbonate stress corrosion cracking. Amine cracking is often intertwined with wet H2S and carbonate cracking, as amines, carbonates and wet sulfides often exist together in amine treating systems.

  • May/June 2004 Inspectioneering Journal
    By John Reynolds at Intertek

    Chloride cracking of austenitic stainless steels (300 series SS) is an off-shoot of CUI, and there’s nothing really magical about it. If you have insulated solid stainless steel equipment operating in the CUI temperature range you are likely to eventually experience External Chloride Stress Corrosion Cracking (ECSCC).

  • January/February 2004 Inspectioneering Journal

    DMW cracking is another fabrication issue that can and does result in equipment failure. It usually occurs at the weld juncture where carbon steel or low alloy steels are welded to austenitic (300 series) stainless steels in high temperature applications. The large difference in coefficient of expansion of the two steels, sometimes exacerbated by thermal cycling, results in cracking at the toe (HAZ) of the weld joining the two materials. Using an austenitic stainless filler material for the DMW junction also increases the stress intensification on the toe of the weld on the ferritic side of the weldment. This type of cracking is most common when temperatures above 800F (425C) are involved, such as in FCCU reactor/regenerations systems, superheaters, reheaters, fired heaters, and hydroprocess equipment. Use of bolted joints, if possible, or nickel base filler materials helps to avoid the DMW cracking problem.

  • January/February 2004 Inspectioneering Journal
    By John Reynolds at Intertek

    Cracks along the toe of a weld are not uncommon during fabrication, and can occur for a wide variety of reasons involving the metallurgy and process control of the the same issues covered above on repair welds can apply to repair welds on castings; especially if you are unaware that the foundry or fabricator is trying to salvage a defective casting by covering up porosity and shrinkage cracking with a big glob of weld metal.

  • Partner Content

    Properly anticipating and finding the damage in your facility is no small task, and spending millions of dollars on inspection may not be getting you anywhere if it’s not the right inspection processes. PinnacleART can use industry best practice models and corrosion expertise to proactively identify damage types, locations and magnitudes so you can ensure you’re performing the right inspections at the right times. Visit us at pinnacleart.com to learn more.

  • November/December 2003 Inspectioneering Journal
    By John Reynolds at Intertek

    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 always), while SOHIC is a type of cracking that can easily lead to failure and needs to be mitigated. HIC is a form of tiny blistering damage that is mostly parallel to the surface and to the direction of hoop stress, hence is usually not damaging until it is extensive and affects material properties or gives rise to step-wise cracking that propagates into a weld or begins to go step-wise through the wall.

  • November/December 2003 Inspectioneering Journal
    By John Reynolds at Intertek

    Carbonate cracking (CC) of carbon steel has seen an increase recently in frequency and severity in some refinery cat crackers, especially in fractionator and gas processing overheads. Some gas scrubbing units are also susceptible. CC is a form of alkaline stress corrosion cracking that often occurs more aggressively at higher pH and higher concentrations of carbonate solutions.

  • November/December 2003 Inspectioneering Journal
    By John Reynolds at Intertek

    Ammonia stress corrosion cracking (SCC) has been around a long time. Most everyone has experienced it from time to time. It's not uncommon in brass tubes in cooling water service that is contaminated with ammonia due to biological growths or other contamination. Sometimes ammonia is added intentionally to process streams as a neutralizer by folks who do not know what it might do to brass tubes. Brass condenser tubes will fail brittlely when bent after they have significant ammonia stress corrosion cracking present. Eddy current inspection of brass tubulars is effective at finding ammonia cracking. Cupro-nickel alloys are usually not susceptible, and if necessary you can upgrade to austenitic stainless steels (which has it's own set of problems).

  • November/December 2003 Inspectioneering Journal
    By John Reynolds at Intertek

    Chloride stress corrosion cracking (SCC) is about as well known as any SCC mechanism can be, so I won't dwell much on it here, but want to mention it for the sake of completeness and hopefully mention something that is not as commonly known about it. Chloride SCC is clearly the bane of austenitic stainless steels and one of the main reasons they are not the "miraclecure" for many corrosion problems.

  • July/August 2003 Inspectioneering Journal
    By John Reynolds at Intertek

    Few of us have not experienced or heard about vibration fatigue (cracking) failures, especially around pumps and compressors. Typically small branch connections, equalizer lines, vents and drains are susceptible, especially if they are screwed connections. Such failures have often led to safety and reliability events because of the sudden release of flammable hydrocarbons.

  • Partner Content

    Visit Pro-Surve May 22-25,2018 along with Calculated Controls at Booth 201 in San Antonio to resolve your difficult maintenance, reliability and inspection issues and let us integrate engineering into an inspection solution for you. Attend technical sessions led by subject matter experts. Interactive round table discussion sessions are also scheduled. Renew acquaintances and ask for a church key!

  • September/October 2001 Inspectioneering Journal
    By W. David Wang at Shell Global Solutions

    Hydrogen-induced cracking is a damage mechanism commonly observed in the petroleum refining industry [1, 2]. The damage appears as laminar cracks and blisters, which can link up in the through-wall direction to form stepwise cracking.

  • May/June 2000 Inspectioneering Journal
    By John Reynolds at Intertek

    This is the first of a series of articles that outlines the 101 essential elements that need to be in place, and functioning well, to preserve and protect the reliability and integrity of pressure equipment (vessels, exchangers, furnaces, boilers, piping, tanks, relief systems) in the refining and petrochemical industry.

  • November/December 1996 Inspectioneering Journal
    By Lynne Kaley at Trinity Bridge LLC / Trinity Bridge Digital, Eivind Johnsen at DNV Inc., and Andy Tallin at DNV Inc.

    Petroleum coke production is an important source of revenue for many refineries. While coking units were initially constructed to deal with a waste product, these units are now of significant economic value.

  • May/June 1995 Inspectioneering Journal
    By Dr. Russell D. Kane at CLI International Inc., and Dr. Michael S. Cayard at Flint Hills Resources

    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 (SSC). Documented cases of leaks and failures of pressure containing equipment have been attributed to these forms of corrosive damage.

    Companies
    Videos related to Cracking
      White Papers related to Cracking
        Downloads & Resources related to Cracking
          Events related to Cracking
            News related to Cracking
              Stay up-to-date with the latest in industry — for free. Join thousands
              of others

              Inspectioneering Journal

              Explore over 20 years of articles written by our team of subject matter experts.

              Company Directory

              Find relevant products, services, and technologies.

              Job Postings

              Discover job opportunities that match your skillset.

              Case Studies

              Learn from the experience of others in the industry.

              Event Calendar

              Find upcoming conferences, training sessions, online events, and more.

              Industry News

              Stay up-to-date with the latest inspection and asset integrity management news.

              Blog

              Read short articles and insights authored by industry experts.

              Acronyms

              Commonly used asset integrity management and inspection acronyms.

              Asset Intelligence Reports

              Download brief primers on various asset integrity management topics.

              Videos

              Watch educational and informative videos directly related to your profession.

              Expert Interviews

              Inspectioneering's archive of interviews with industry subject matter experts.