It is important for the improvement of mechanical properties quenching and partitioning (QP) steels to control martensite transformation behavior stability untransformed austenite. In this study, we evaluated restart temperature (Mr) via a dilatometer during reheat austempering pattern. This heat pattern corresponding typical treatment QP steel involves TQ, between start (Ms) finish temperature...

Evaluation of Temperature-Time Profiles by the Lumped Thermal Mass analysis method for bottom surface jet impingement cooling system was carried out. This done controlled accelerated using a modified run-out table (ROT). The evaluation with variant pipe diameters 10mm - 40mm single water jet, having gaps in range 55mm 95mm and sub-cooled to 150oC – 110oC. results revealed that rate faster at an...

Structural steels with very high strength levels are often referred to as ultrahigh-strength steels (UHSS). The usage of UHSS has been extensively studied in aerospace industries and offshore platforms. In this study, medium carbon low alloy steel (AMS6305) was thermomechanicaly treated to obtain an ultra-high strength bainitic steel for aircraft engine compressor disk. A novel themomechanical ...

In conventional steels, bainitic microstructure which forms under isothermal conditions consists of ferrite and carbide precipitates whose distribution size substantially depend on the pa-rameters treatment. CFB steels (Carbide Free Bainite) however, main micro-structural constituents are ferrite, retained austenite and, sometimes, M-A constituent. may possess better ductility same or even high...

Incomplete bainitic transformation during austempering treatment is mainly caused by the supersatu-ration of austenite with carbon. Such supersaturated becomes more stable and further stabi-lization led silicon alloying. Stable does not transform remains in structure as so-called residual austenite. Therefore, carbides, which are desirable a conventional struc-ture, cannot be formed carbide fre...

Samples of ductile iron alloyed with 0.88 % Ni a nodule count 606, 523, and 290 nod/mm2 were obtained from sand cast plates different thickness in the range 8.46 to 25.4 mm. The effect was evaluated during austempering process held at 285?C times 15, 30, 45, 60, 70, 90 min. volume fraction high carbon austenite increased when increased, however, content kept almost constant. window narrow, requ...