Abstract: Austenitized ferrous metal, such as carbon steel, is quenched by means of an aqueous solution of a salt of polyacrylic acid which develops an extremely stable and uniform water vapor envelope surrounding the steel. Rate of cooling is controlled by (1) the molecular weight of the salt, (2) concentration of the salt in the solution, (3) solution temperature, and (4) the degree of agitation of the quenchant solution. In the case of carbon steel, by proper selection of the above variables, the austenitic structure of the hot steel may be directly transformed into non-martensitic structures of improved ductility, machinability and cold working properties, such as fine striped pearlite, without the necessity of further heat treatments, such as tempering, following quenching.The quenching solution may also be used to quench parts formed of alloy steel to obtain a martensitic structure without unwanted cracking and distortion. Non-ferrous metals may also be quenched using the polyacrylate quenching solution.