1979 Volume 48 Issue 7 Pages 468-475
A possibility of cold cracking in the heat affected zone (HAZ) of heavy section steel forging during stainless steel overlay cladding was investigated.
The results of the study obtained are summarized as follows:
1) The hydrogen embrittlement of HAZ below 120°C is remarkable, especially at room temperature. Even a small amount of hydrogen of about 1.5 ppm decreases the lower critical stress.
2) The hydrogen contained in the deposited stainless steel metal diffuses into HAZ of the base metal and is able to be a source of hydrogen induced cracking.
3) Over 0.5 % restricted strain, the hydrogen induced cracking will be occurred in HAZ, if the welding conditions, such as preheat and postweld heat treatments, are not appropriate.
4) It is necessary to maintain the preheat temperature of 120°C or over during entire welding process, in order to prevent the hydrogen induced cracking under the heavily restricted condition in the large heavy section steel forgings.