Continuous annealing method for low coercive force cold-rolled electromagnetic pure iron plate and strip

Abstract

A continuous annealing method for low coercive force cold-rolled electromagnetic pure iron plate and strip. Control parameters of each stages in a continuous annealing process are as follows: 750-850° C. at a heating stage; 750-850° C. at a soaking stage, the soaking time is 100-150 s; an outlet temperature of 575-675° C. at a slow-cooling stage, the cooling speed in slow-cooling stage is 2.5-10° C./s; an outlet temperature of 380-420° C. at a fast-cooling stage, the cooling speed of the fast-cooling stage is 15-25° C./s; and 270-310° C. at an overaging stage. The annealing medium is a non-oxidizing atmosphere composed of Hand N. After annealing, the cold-rolled electromagnetic pure iron plate and strip is leveled and pressed such that the leveling elongation rate of the plate and strip is controlled within the range of 0.2±0.1%. The process of the continuous annealing method is simple, and the produced cold-rolled electromagnetic pure iron plate and strip can achieve an overall performance of low coercive force and good formability without further magnetic annealing.