A cryogenic treatment influence on steel tool AISI T-2000 mechanical properties

This paper evaluated the effect of cryogenic treatment on the mechanical properties and microstructure of AISI tool steel T 2000. The tests (Tensile, Impact, Hardness, Microscopy) and toughness were carried out to the specimens with and without Cryogenic Heat Treatment, this treatment is carried out by immersing the samples in liquid nitrogen at 194 degrees C for 24 hours, for comparison with the cryogenically not treated. The fracture characteristics of the samples were evaluated by Scanning Electron Microscopy (SEM), with the predominant mechanism of cleavage fracture. Evidenced that the mechanical properties improved significantly in the samples with cryogenic treatment relative to untreated samples. The microstructure before and after treatment possible to observe the transformation of retained austenite to marten site, which is a key to improve the mechanical properties and microstructure of the steel.