Definition - What does Creep-Rupture Embrittlement mean?
Creep-rupture embrittlement is embrittlement that takes place under creep conditions, such as in steels and aluminum alloys, that leads to rupture ductility that is abnormally low.
In the case of aluminum alloys, amounts of iron above the limit of solubility can lead to embrittlement. In steels, this occurrence is associated with the presence of impurities such as:
In each situation, the failure occurs due to intergranular corrosion or cracking involving the embrittled matter.
Corrosionpedia explains Creep-Rupture Embrittlement
Creep takes place under load exposed to high temperatures. Gas turbines, ovens and boilers are just a few systems consisting of elements that undergo creep. A better understanding of the behavior of various materials in high temperatures can be useful in gauging the failures in such systems.
The failures related to creep are typically easy to determine because of the deformation that takes place. These failures may become brittle or ductile. Additionally, the cracking may be either intergranular or transgranular. Although creep testing can be performed under constant load and temperature, the actual elements may become damaged at certain loading conditions and temperatures.
Such conditions could lead to temper embrittlement that decreases the toughness of steels when cooled or heated. This is also caused by the existing impurities in steel that undergo segregation before austenite grain margins during heat treatment. The embrittled surface appears intergranular due to the fracture or damage on the surface.
Creep and stress rupture tests should be employed by industries to identify the time that leads to failure. Having a good understanding of the structural changes in materials is highly beneficial in preventing errors and further failures in data extrapolation and industrial operations.