|Measurement of martensitic packet size by EBSD in the high strength steel X38CrMoV5-1 and estimation of its influence on cleavage fracture|
PASTOR, A., VALLES, P., PÉREZ, P., MEDINA, S. F.
vol. 58 (2020), no. 4, pp. 267 - 273
The crystallographic packet or microstructural unit was determined with 15° and 5° boundary grain misorientations in a quenched and tempered X38CrMoV5-1 steel, yielding results of 0.68 and 0.59 μm, respectively. Though both values are similar, the latter has been taken as the best to calculate the effective surface energy of cleavage fracture, γp, leading to a value of 15.8 J m–2. Thus it is demonstrated that the microstructural unit controlling crack propagation is that determined by EBSD with a 5° misorientation angle. Other structural parameters, like the parent austenite grain size and the morphological martensitic packet, have been ruled out.
EBSD, crack growth, fracture toughness, precipitation, steel
Full text (1210 KB)