EFFECT OF AUSTENITE GRAIN MORPHOLOGY ON VARIANT SELECTION OF MARTENSITE TRANSFORMED FROM ULTRAFINE-GRAINED AUSTENITE

Microstructures of Pearlite and Martensite Transformed from Ultrafine-Grained Austenite Fabricated through Cyclic Heat Treatment in Medium Carbon Steels

This study investigated the microstructures of pearlite and martensite transformed from ultrafine-grained austenite in 0.45C steel and Vadded 0.45C steel. The mean prior austenite grain sizes were refined to be 4.5 μm in the 0.45C specimen and 2.4 μm in the V-added 0.45C specimen through cyclic heat treatment of austenitizing and water quenching, i.e., repetition of martensite § austenite trans...

Martensite ? austenite phase transformation kinetics in an ultrafine-grained metastable austenitic stainless steel

A generalized phase transformation kinetics model is used to understand the martensite to austenite transformation in a cold-rolled and annealed metastable AISI 301LN ultrafine-grained austenitic stainless steel. The model shows that the presence of interstitial nitrogen and heavy cold-rolling is important to promote fast transformation kinetics, through rapid nitrogen-diffusion and austenite n...

Research on abnormal grain growth in reversely transformed austenite structure

Simulation of an Austenite-Twinned-Martensite Interface

Developing numerical methods for predicting microstructure in materials is a large and important research area. Two examples of material microstructures are Austenite and Martensite. Austenite is a microscopic phase with simple crystallographic structure while Martensite is one with a more complex structure. One important task in materials science is the development of numerical procedures whic...

Austenite Stability during Nanoindentation of Ultrafine and Coarse Grained AISI 304L Stainless Steels

In the present study, the effect of grain size on the austenite stability was studied by nanoindentation tests in a 304L stainless steel. Thermomechanical processing based on cold rolling and annealing was used to produce two different types of austenite: ultrafine grained (UFG) austenite with the average grain size of 0.65 μm and coarse grained (CG) austenite with the average grain size of 12 ...

Stabilization of Austenite Associated with Prior Formation of Martensite

The stabilization of retained austenite was studied via a two-step cooling procedure. Alloys with M , temperatures below 0 OC were used. It was found that the martensitic transformation starting temperature, M,, was lowered to M,' during the second step of cooling. With increasing the amount of previously formed martensite, the difference in the transformation starting temperatures, AM, (= M,M,...