Aq. quenching baths for metal heat treatment - contg. salt of copolymer of alpha-olefin and unsatd. dicarboxylic acid

摘要

Aq. quenching baths for use in heat treatment of metals comprise an aq. soln. contg. 0.2-10 esp. 0.5-5 wt.% (expressed as anhydride) of a water soluble salt of a copolymer, contg. units (CHR-CH2-X-)n where X is (a) -CR'(COOM)-CH(COOM)- or (b) -CH2-C(COOM)(CH2COOM); R is (branched) alkyl having an 8-28C backbone; R' is H or methyl; M is an alkali metal, ammonium, lower alkyl amine or water soluble alkanolamine cation; and n is such that the copolymer mol. wt. is 25000-250000. The solns. are useful in quenching metal at cooling rates which are slower than that of water and as slow or slower than those obtd. using a hydrocarbon oil medium. The viscosity of the solns. does not vary significantly with the copolymer concn. The solns. are esp. useful for cooling austenitised ferrous metal to produce non-martensitic or martensitic microstructures.