Fig. 1: Maps of the deviatoric strain of the B2 austenite along the vertical y axis (εyy) from x-ray diffraction analysis. The global displacements for these maps are shown in the upper left corner of each image. The dark lines illustrate the approximate location of the edges of the diamond strut. The red color indicates tensile strain whereas blue indicates compressive strain; note also the pr...

During the summer of 2006, I had the opportunity to participate in an internship through the U.S. Department of Energy (DOE) at Oak Ridge National Laboratory (ORNL). ORNL is the nations largest national laboratory that is funded by the DOE. ORNL is known best for developing the technology for the atomic bomb and was a classified area for many years. Today ORNL’s research spans all areas of scie...

The medium Mn steels are gaining increasing attention due to their excellent combination of mechanical properties and material cost. A cold-rolled 0.1C5Mn medium Mn steel with a ferrite matrix plus metastable austenite duplex microstructure was resistance spot-welded with various welding currents and times. The nugget size rose with the increase of heat input, but when the welding current excee...

Knowledge of carbon content in retained austenite (RA) with different neighbouring phases is essential to understand the chemical stability of RA, which is useful for microstructure tuning of transformation-induced plasticity (TRIP) steels. The present study investigates different morphologies and chemical compositions of RA by correlating electron backscattering diffraction, transmission elect...

Microstructural evolutions during annealing of cold rolled AISI 304L and AISI 316L stainless steels were studied. Cold rolled AISI 304L alloy was fully martensitic but cold rolled AISI 316L alloy was partially martensitic due to the higher stability of the austenite phase in the latter. During continuous heating to elevated temperatures, the complete reversion of strain-induced martensite at 75...

Present investigations involve a systematic study on the machinability of austempered ductile irons (ADI) developed from four commercially viable ductile irons alloyed with different contents of 0, 0.1, 0.3 and 0.6 wt.% of Ni. The influence of Ni content, amount of retained austenite and hardness of ADI on machining behavior has been conducted systematically. Austempering heat treatment was car...

To investigate the effect of tempering treatment on mechanical properties and the microstructure of DIN 1.4021 Martensitic Stainless Steel, austenite treatment was conducted for the samples at 1000 ºC temperature for 60 min and then the samples were oil quenched. Later, tempering treatments were performed for the samples at 500 ºC and 700 ºC temperatures for 2 and 5 h, respectively; then quench...

Retained austenite is a key feature used to realize the transformation-induced plasticity in bainitic high strength steels. In this study, authors focused on formation of metastable Fe-0.61C-1.9Si-0.98Mn (mass%) during isothermal heating processes using situ neutron diffraction techniques. Quantitative discussion carbon partitioning enabled by applying an phase fraction analysis considering cry...