Abstract
Strengthening mechanism of ausforming were investigated for some alloy steels.
Thin foils taken from ausformed alloy steels showed that special carbides could be directly formed at subboundaries in the deformed austenite. Carbon extraction replica also showed that carbides distributed along cell boundaries in ausformed martensite after tempering, while in directly transformed one carbides were extracted along lath boundaries. Furthermore, by means of direct observation, both austenite and - martensite subjected to ausforming were revealed to have a cell structures.
From the above results, it was suggested that the structure having a number of cells which had been developed in austenite during ausforming was introduced to martensite through the transformation. In such an inheritance, carbide precipitates on the dislocation network should have an important role.
It will be discussed that the cellular structure is responsible to the strengthening by ausforming.
