High temperature properties of 2 1/4Cr-1Mo steel weld metals

2 ¼ Cr-lMo is a low-alloy ferritic steel used primarily for high temperature applications. While extensive data exists on 2zCr-lMo in wrought and cast forms, scant information is available on the high temperature properties of 2 ¼ Cr-IMo weld metal. Since welding is the primary fabrication method used with 2 ¼ Cr-lMo, the paucity of weld metal data is a matter of concern to the designers of pressure vessels constructed of 2aCr-lMo. The current study was initiated in response to the need for more weld metal data.

Stress-rupture tests were conducted at 850 F, 950 F and 1050 F on 24Cr-lMo weld metals deposited by the shielded metal arc (SMAw), submerged arc (SAw) and electroslag (ESw) welding processes. Room temperature and elevated temperature tension tests were also performed.

The stress-rupture strength of 2kCr-lMo weld metal was shown to be a function of welding process characteristics, carbon content, and PwHT. The stress-rupture strength of 2zCr-lMo weld metal was found to increase with increasing carbon content. Creep ductility in 2 ¼ Cr-lMo weld metal was shown to be independent of rupture time, but dependent on carbon content. Room temperature tension tests did not correlate directly with elevated temperature stress-rupture behavior, but a good correlation with stress-rupture behavior was observed with regard to the elevated temperature tensile properties.

The current study has shown the need for additional work in related areas, particularly the investigation of weldments with different carbon contents than those utilized in this study and of weldments produced by different welding processes, such as electron beam and gas tungsten arc welding.