METHOD OF HEAT TREATMENT OF TUBE CENTRIFUGALLY CAST FROM HIGH-STRENGTH CAST IRON WITH GLOBULAR GRAPHITE

摘要

FIELD: ferrous metallurgy; heat treatment for annealing of centrifugally cast tubes. SUBSTANCE: method consists in heating to annealing temperature of 840 to 870 C and keeping at this temperature for 1-2 hours followed by specified cooling. Rate of heating the tube ranges from 4 to 40 C/min and specified cooling is effected at rate of 0.5 to 10 C from annealing temperature to temperature of 690-730 C after which cooling is completed in air any rate. EFFECT: improved quality of tube due to enhanced mechanical properties and deformability. 1 tbl