It can be seen in the above picture of the open gamma field; the gamma region is expanded by raising gamma to delta transformation region and by depressing gamma to alpha transformation region. Elements that have this type of effect of phase transformation are Nickel, Manganese, Cobalt, and inert metals such as platinum. If we add Nickel and Manganese in fairly high amounts, then it is possible to stabilize austenite at a high temperature which can be clearly seen in the picture that the A3 and A1 line completely vanishes at high concentration of alloying elements. With austenite stable at high room temperature, Austenitic steel are developed using high concentration of Nickel and Manganese.