Stress Relaxation Cracking

Mon, 01 Jan 0001 00:00:00 +0000

General Information

Interest in Stress Relaxation Cracking, sometimes referred to as Reheat Cracking, Stress Relief Cracking, or Strain Oxidation Cracking, began to rise approximately 20-30 years ago. This increase coincided with a growing number of “mysterious” failures observed in austenitic stainless steels and nickel alloys operating within theoretically safe temperature ranges. Failures of welded pipelines and equipment made from high-temperature stainless steels (such as 321ss - UNS S32100) or nickel alloys (such as 800H - UNS N08810), characterized by an intergranular cracking pattern, were often attributed to modes such as creep cracking assisted by oxidation.¹ ² ³ Studies by van Wortel and others have confirmed that the relaxation of accumulated stress, particularly in cold-worked areas such as bends or near welds’ Heat-Affected Zones (HAZ), aided by high temperatures (typically below the maximum service temperature limits for the given steel), is the primary driver for SRC.⁵

Mechanical-Metallurgical Failures on Knowledge Library

Stress Relaxation Cracking

General Information