NEW DIRECTION IN LIQUID QUENCHING MEDIA DEVELOPMENT

Abstract

It is shown that in contrast to well known surface active additives (SAA), affecting physical properties of a liquid, the elimination of film boiling during quenching is achieved by creation of the thin polymeric layer on the surface of hardened metal. It is performed by using special polymers of optimal concentration in water. The obtained insulating polymeric layer decreases initial heat flux density below its critical value and by this way eliminates completely the film boiling without affecting clearly the physical properties of a liquid.     Based on this fact and on the principle of decreasing distortion, quench crack formation, and increasing strength of material during intensive quenching,  it is proposed to use low concentration of special polymers instead of their high concentration in water. All of this results in significant strengthening of metal, saves costly materials, and increases service life of hardened products.