Effect of pearlitic and bainitic initial microstructure on cementite spheroidization in rail steels

Control of the metallographic and mechanical properties of Cr8 cold-work die steel by laser continuous/dispersed quenching

“…noting that in the case of specimens subjected to dispersed laser hardening, UBS and εf of specimens treated by LDQ are about 1086.2 MP and3.8%, significantly higher than those observed in specimens treated with LCQ. Compared to LCQ treatment, selective laser hardening in graphical form not only enhances the material's bending yield strength (σb0.2) but also its ultimate bending yield strength (UBS) [23,25,26]. Moreover, the fracture strain is notably increased by dispersed laser heat treatment, indicating exceptional plastic deformation capabilities during bending, consistent with previous studies.…”

“…This is attributed to the presence of fine carbide particles, which impede stress release through slip and thus induce relative rotation deformation for stress relaxation and specimen continuity maintenance. In Figure17(c), the smaller-sized carbides and martensitic matrix remain unchanged in shape, while a minor fraction of carbides undergo noticeable deformation[25,27]. Undistorted carbides with a diameter of approximately 1 μm are still observable at the hardening unit, indicating significant deformation differences between the substrate and the hardening unit during bending processes.…”

Quasi-equal strength and toughness matching rail steel joint obtained via friction welding below Ac1 temperature

“…1,2 Despite their widespread use, these welding methods often encounter a significant challenge: the weld thermal cycles and subsequent post-weld heat treatment (PWHT) can result in a non-uniform surface hardness zone spanning tens of millimetres. 3 This zone comprises both hardened and softened subzones, 4 leading to mechanical property discrepancies between the joined region and the steel rail itself. 5,6 Additionally, these welded joints are required to withstand the same load of rolling contact fatigue as the high-strength steel rail during their service.…”

Crystallization of FeC Iron Monocarbide During Peritectoidal Transformation of the Lamellar Eutectoid of Ledeburite White Eutectic Cast Iron

“…The study of the decay of martensite, perlite and quasi-perlite structures has been carried out in a number of works [25][26][27][28][29]. Pereira H.B.…”