text: how can i determine the amount of retained austenite in ss after heat treatment in a practical way?(not x-ray) heat treatment is continuous process and steel is under eutectoid stainless steel with 0,1 mm thickness. the easiest way is to section the steel, grind and polish it, and then etch it.  then you can use a simple light microscope to visually see the phases and quantify their respective ammounts.  if the specimen is small you could also examine it in a sem using similar techniques.