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Severe Sour Service

When you choose a steel product for use in a particular application, the environment in which that product will be used is critical in determining which material should be used. The components of our SA 516 (Hydrogen (H2S) Induced Cracking – HIC) and SA 516 vacuum degassed – TUF 37- are designed to contain extra low sulfur, phosphorus and similar residual elements, and for maximum resistance to sulfide stress corrosion, HIC, and notch toughness sensitivity.

These plates are used in the pressure vessel industry and primarily in refineries, chemical plants, and power plants.

Hydrogen Induced Cracking – HIC

HIC can be affected by a variety of factors, including, among others:

  • Concentration of hydrogen.
  • Material strength.
  • Cold work.

The selection of the proper materials, testing and fabrication are all essential elements in the production of an effective steel product for sour service.

Material Selection for Sour Service Applications

In order to ensure that a steel product is both safe and reliable for sour service applications, we employ the following steel products to deal effectively with the environment in which the steel is used.

TUF-37 Grades

American Alloy Steel ‘s TUF-37 is available in grades 60, 65 and 70. It is produced with stringent adherence to specifications so that our customers are assured that when used, the product with have the greatest resistance to:

  • Notch toughness sensitivity.
  • Stress corrosion cracking.
  • Hydrogen induced cracking.

Heats are vacuum degassed and calcium treated for sulfide shape control. Upon request, TUF 37 may be examined ultrasonically per ASME SA-435 or SA-578 Level 1.

TUF 37 – HIC Grades

These grades are nearly identical to TUF 37 grades and are HIC resistant carbon steel plates. They provide corrosion toughness and crack resistance to hydrogen sulfides. We perform HIC testing pursuant to NACE Standard TM0284, Crack Length Ratio (CLR), Crack Thickness Ratio (CTR) and Crack Sensitivity Ratio (CSR). The resulting product yields outstanding results and quality steel plate.

They are available from our stock in full or cut to size plates. Sizes are from

  • Thickness of ¼ to 6.
  • Width of 72, 96, 120 and 14.
  • Lengths of 240, 360 and 480.

While the TUF 37 / HIC grades are generally comparable to TUF 37, the HIC grades are further restricted in residual elements such as extra low sulfur and phosphorous. In addition, hydrogen induced cracking tests are performed in accordance with NACE Standard TM0284-96 with test solution A. Upon request, these grades can be Charpy impact tested pursuant to SA-20, or they may be examined pursuant to other testing requirements.

Assuring Outstanding Quality for Our Customers

All TUF 37 plate orders, whether shipped from our existing stock or from the production mill, include Certified Test Reports. This assures that our customers receive the ultimate in quality for their intended application.

AA Steel can provide plates cut to size, with shipments scheduled to meet your requirements. Contact us for further information or to order our TUF 37/TUF 37 – HIC grades for your project.