Low-Cost Grain Oriented Silicon Steels Manufactured by Continuous Annealing

Abstract

Low-cost grain oriented silicon steel produced by continuous annealing, low slab-heating temperature, and omitting normalization annealing is explored and analyzed. This type of grain oriented steel is designed to replace the non-oriented steels used for the production of transformers of medium and small sizes as specified in all GO steel producers catalogs. Fully secondarily recrystallized structure with magnetic properties of P1.7 ¼ 2.04 W kg À1 and B8 ¼ 1.76 T is obtained at temperature of 1050 8C within 10 min in the condition of two-stage cold rolling, whereas one-stage cold rolling method fails to initiate abnormal grain growth in the same processing parameters. The success of fully secondary recrystallization using two-stage cold rolling method is ascribed to the more important role of sufficient amount of Goss seeds in decarburized samples as in CGO steels than the stronger {111}<112> texture as in HiB silicon steels. It is further determined that by two-stage cold rolling technique, a higher secondary stage rolling reduction leads to a lower secondary recrystallization starting temperature and a shorter secondary recrystallization staring time related with a finer grain size. The reasons for the high iron core loss related by continuous annealing are connected to the higher number of deviated Goss grains scattering toward {210}<001> or Brass orientations, the residual inhibitors and the imperfect grain size and morphologies. The reasons for the failure in abnormal grain growth by one-stage rolling are also discussed.

Development of a virtual shapemeter based on a shape control model for continuous annealing

“…Continuous annealing integrates cleaning, annealing, levelling and finishing, and has the advantages of a short production cycle, high yield, product diversification and high-quality products, improved properties and shape (Nishchik et al, 2016;Hou et al, 2018;Jiao et al, 2016). As an important process in the production of high-grade cold-rolled strip, continuous annealing provides raw material for subsequent levelling, so strip shape precision is important to the shape of finished product (Ma et al, 2017).…”

Secondary Recrystallization Behavior in Fe-3%Si Grain-oriented Silicon Steel Produced by Twin-roll Casting and Simplified Secondary Annealing

“…They demonstrated that the kinetic of secondary recrystallization was significantly accelerated by strain induced boundary migration mechanism. Recently, Jiao [16] reported a low-cost grain-oriented silicon steel manufacturing method by using a reduced inhibition state and two-stage cold rolling, and the secondary recrystallization was complete in continuous annealing. Furthermore, Lu [17] observed that some non-Goss {110} <227> grains abnormally grew during short-term isothermal secondary annealing in strip-cast Fe-4.5%Si grain-oriented silicon steel, and deemed that this non-Goss abnormal growth would lead to the decrease of magnetic properties.…”

Modelling and simulation of residual stress of strip during continuous annealing process

“…Cleaning, annealing, leveling and finishing can be merged because of the continuous annealing process line (CAPL) that uses rapid heating, high-temperature annealing, rapid cooling and overaging treatment technologies (Jiang et al, 2016). A product with good flatness, uniform performance, and the surface of high cleanliness can be produced at a lower cost (Jiao et al, 2016). Thus, this CAPL has rapidly developed (Zheng et al, 2017).…”