Forging bursts are infrequently reported in the published literature. One type of forging burst, which has been observed only on four occasions in the combined experience of the authors, is described. The similarity of this defect with hydrogen-caused thermal flakes is remarkable. It is characterized by a fracture appearance similar to that of flaking when broken open, by orientation and distribution similar to flaking, but within a specific section of a large forging, generally in ultrasonic test response and by its good response to healing during reforging, as with flaking.
Case histories of two 3.5Ni-Cr-Mo-V forgings, one 1cr-1Mo-0.25v forging and one martensitic stainless steel forging are presented, and processing factors related to these bursts and means for avoidance of the problem are discussed. A fifth case of possible misidentification of this phenomenon as hydrogen flakes in a small gear component forging is discussed. Approaches to differentiation of this defect from flaking are discussed.