Method of producing grain-oriented electrical steel sheet

摘要

In a method of producing a grain-oriented electrical steel sheet by hot-rolling a steel slab of a chemical composition containing C: 0.001˜0.10%, Si: 1.0˜5.0%, Mn: 0.01˜1.0%, at least one of S and Se: 0.01˜0.05% in total, sol. Al: 0.003˜0.050%, N: 0.001˜0.020% by mass, subjecting to cold rolling, a primary recrystallization annealing, application of an annealing separator mainly composed of MgO and a finish annealing, a temperature rising rate S1 between 500˜600° C. in the primary recrystallization annealing is made to not less than 100° C./s and a temperature rising rate S2 between 600˜700° C. is made to 30° C./s˜0.6×S1° C./s, while a total content W (mol %) of an element having an ionic radius of 0.6˜1.3 Å and an attracting force between the ion and oxygen of not more than 0.7 Å−2 included in the annealing separator to MgO is adjusted to satisfy 0.01S2−5.5≦Ln (W)≦0.01S2−4.3 to produce a grain-oriented electrical steel sheet having excellent iron loss properties and coating properties.

主权项

1. A method of producing a grain-oriented electrical steel sheet by hot-rolling a steel slab of a chemical composition comprising C: 0.001 to 0.10 mass %, Si: 1.0 to 5.0 mass %, Mn: 0.01 to 1.0 mass %, at least one of S and Se: 0.01 to 0.05 mass % in total, sol. Al: 0.003 to 0.050 mass %, N: 0.001 to 0.020 mass % and the balance being Fe and inevitable impurities, subjecting to single cold rolling or two or more cold rollings including an intermediate annealing therebetween to a final thickness and further to a primary recrystallization annealing, application of an annealing separator composed mainly of MgO and a finish annealing, wherein the primary recrystallization annealing a temperature rising rate S1 between 500 to 600° C. is made to not less than 100° C./s and a temperature rising rate S2 between 600 to 700° C. is made to 30° C./s to 0.6×S1° C./s, while a total content W (mol %) of an element having an ionic radius of 0.6 to 1.3 Å and an attracting force between ion and oxygen of not more than 0.7 Å−2 included in the annealing separator to MgO is adjusted to satisfy the following equation (1) in relation to the S2:
0.01S2−5.5≦Ln(W)≦0.01S2−4.3  (1).