Hydrogen in heavy wall submerged arc weld-joints of 2 1/4 Cr- 1 Mo steel after different soaking treatments
The very important necessity of preventing hydrogen-induced cracks during the welding of 2 1/4 Cr - 1 Mo vessels requires reliable specifications for the dehydrogenation of the welded joints. A real evaluation of the hydrogen risk can only be based on actual figures which have been determined in original joints. For the tests, a 4-3/4 in. (120 mm) thick plate of 2-1/4 Cr - I Mo steel was used. Submerged arc welding was performed with an EB-3 wire and an agglomerated flux which has been used in the past decade for the above application. Immediately after welding, three different dehydrogenation treatments were performed: 2 h at 535{degrees}F (280{degrees}C), 4 h at 660{degrees}F (250{degrees}C), and 1 h at 1150{degrees}F (620{degrees}C). The results show that in all cases, the maximum level of hydrogen was found in the upper half of the joint. Especially interesting are the results of the diffusible hydrogen since its level is directly responsible for the delayed hydrogen cracks. The recommendation gained from the performed investigations is to modify the often-raised requirements of an intermediate stress relieving of highly stressed weldments. Both treatments, 2 h at 535{degrees}F (280{degrees}C) and 4 h at 660{degrees}F (250{degrees}C), result in a diffusible hydrogen content significantly below the critical limit. The application of 4 h at 550{degrees}F (250{degrees}C) even leads to hydrogen contents which are nearly as low as given by an intermediate stress relieving.
- OSTI ID:
- 115499
- Report Number(s):
- CONF-9404233-; TRN: 95:002927-0077
- Resource Relation:
- Conference: 75. American Welding Society (AWS) annual meeting, Philadelphia, PA (United States), 10-15 Apr 1994; Other Information: PBD: 1994; Related Information: Is Part Of 75th Diamond anniversary American Welding Society annual meeting; PB: 273 p.
- Country of Publication:
- United States
- Language:
- English
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