The effect of the initial microstructure and soft annealing temperature on cementite spheroidization softening is studied an AISI 5140 hot-rolled wire. In coarse pearlite (λ: 0.27 μm), progresses slowly under subcritical treatment, does not achieve minimum G2/L2 IFI rating defined in ASTM F2282 to be used cold forming operations any treatment studies. Fine 0.10 μm) upper bainite microstructures...

This study consists of the experimental and numerical analysis phase transformations 5Cr-0.5Mo.0.1C steel after heat treatment. The microstructure as-received comprised ferrite bainite, which is in agreement with microconstituents predicted by Calphad-calculated TTT diagram. Calphad-based precipitation calculations show that cooling stage normalizing treatment did not cause carbide formation. I...

Abstract The microstructure of a low alloy medium carbon bainitic steel, austempered in the temperature range 275 °C to 450 has been investigated by detailed electron backscatter diffraction and variant pairing analysis. It is observed that tendency two distinct changes with varying temperature. At V1-V6 most frequent, whereas V1-V2 frequent at intermediate highest temperature, V1-V4 dominates....

The combined influence of prior plastic strain in the austenite, and applied stress in the course of the transformation, on the crystallographic texture of a bainitic steel was studied in this work. The experimental data were obtained using Electron Back Scatter Diffraction (EBSD) method and analyzed using two methodologically different approaches. It was concluded that the plastic deformation ...

AISI 4340 steel is one of the super strong steels that can be selected for different applications. By designing the proper cycles of heat treatment, the optimum microstructure and properties of this steel can be achieved. In this study, different heat treatment cycles were introduced to achieve the optimum microstructure and improve the mechanical and magnetic properties of AISI 4340 steel. The...

The quenching and partitioning (Q&P) process is an advanced method of heat treatment high-strength steels. resulting properties Q&P-processed steels are dictated by their microstructure which consists tempered martensite, fresh martensite retained austenite (RA). These phases arise from individual steps the Q&P-process. An important step stabilization austen-ite because RA raises du...

The influence of bainite morphology on the impact toughness behaviour of a continuously cooled cementite free low carbon C-Mn-B type of steel has been examined. Different bainite morphologies were obtained by cooling from the austenite regime to ambient temperature with different cooling rates. The resulting microstructures have been quantitatively analysed using light optical microscopy (LOM),...

The resistance to hydrogen embrittlement is of essential importance for steels for vessels for storage of hydrocarbons and depends on the effect of absorbed hydrogen on steel ductility. API tests have shown for the 490 MPa yield stress HSLA steels with the microstructure of ferrite and cementite particles a much greater reduction of area than for the 350 MPa steel with the microstructure of pol...

The effect of austenite grain size on the evolution of the bainite transformation in steels is not yet certain in spite of many investigations.1–7 Barford and Owen1 reported that the reaction rate was accelerated by decreasing the grain size, because of an increase in the number density of grain boundary nucleation sites. Umemoto et al.2 reported similar results and proposed an equation that de...