Abstract: This invention not only improves the formation of fine crystal structure and hence the magnetic properties as well as surface properties while utilizing the merits of the hot strip mill at maximum by conducting the rough rolling in the steps for the production of grain oriented silicon steel sheets, particularly hot rolling step at a high temperature and a large draft, but also stably achieves the more improvement of the magnetic properties under a high reliability by accurately controlling the precipitation state of inhibitor at a finish rolling stage in the hot rolling step.

Abstract: The substituted alkylamine derivatives represented by formula (I) ##STR1## wherein R.sup.1 represents (a) substituted or unsubstituted C.sub.2-6 alkenyl group, (b) substituted or unsubstituted C.sub.3-6 cycloalkenyl group, (c) substituted or unsubstituted C.sub.2-6 alkynyl group, (d) substituted or unsubstituted aryl group, (e) substituted or unsubstituted heterocyclic group, (f) fused heterocyclic group which may be substituted, or (g) group represented by the formula Ru.sup.11 -Ar wherein R.sup.11 is a heterocyclic group and Ar is a 5- or 6-membered aromatic ring which may contain a hetero N, O or S atom, and which may be substituted; ##STR2## represents a 5- or 6-membered aromatic ring which may contain a hetero N, O or S atom, and may be substituted by R.sup.7,X and Y are linking groups,R.sup.2 is H or lower alkyl,R.sup.3 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl or lower cycloalkyl,R.sup.4 and R.sup.5 are independently hydrogen or halogen atoms,R.sup.

Abstract: The present invention realizes the stable production of grain oriented silicon steel sheets having excellent magnetic properties under high productivity through effectively combining aging treatment with tandem rolling, in which cold rolling is effected until a final thickness is attained. In the final cold rolling step of the production of the grain oriented silicon steel sheets, the tandem rolling is first effected, and then continuous heat treatment is effected, preferably under application of tension.

Abstract: A grain-oriented silicon steel sheet having a low iron loss free from deterioration due to the stress-relief annealing, can be obtained by forming on its surface a forsterite film locally having regions, which have a thickness different from that of the remaining regions in the film, or locally having filmless regions which do not coat the steel sheet surface.

Abstract: The magnetic properties, particularly magnetic flux density of a grain oriented silicon steel sheet are considerably improved by continuously and/or stepwise forming regions, wherein a temperature difference of a secondary recrystallization starting temperature in widthwise direction and/or longitudinal direction of the steel sheet is within a range of 10.degree. C. to 200.degree. C., in the steel sheet at a stage before the secondary recrystallization annealing step.

Abstract: A grain-oriented silicon steel sheet having a low iron loss, due to the subdividing effect of magnetic domain wall spacing, free from deterioration due to the stress-relief annealing, can be obtained by forming on its surface a forsterite film locally having regions, which have a thickness different from that of the remaining regions in the film, or locally having filmless regions which do not coat the steel sheet surface.

Abstract: A substituted pyridine derivative represented by the general formula ##STR1## wherein R.sup.1 represents a phenyl or naphthyl group which may optionally be substituted by a substituent selected from the class consisting of a hydroxyl group, lower alkyl groups, lower alkoxy groups, cycloalkyl groups, lower alkoxycarbonyl groups, a phenyl group and halogen atoms; X represents an oxygen atom, a sulfur atom, a carbonyl group, or a group of the formula --CH(OH)-- or --N(R.sup.a)-- in which R.sup.a is a hydrogen atom or a lower alkyl group; Y represents a linear or branched lower alkylene group or a vinylene group which may optionally be substituted by a lower alkyl group, with the proviso that when X is an oxygen or sulfur atom, Y represents the lower alkylene group; R.sup.2 and R.sup.3 are identical or different and each represents a hydrogen atom or a lower alkyl group; R.sup.

Abstract: A grain-oriented silicon steel sheet having a low iron loss free from deterioration due to the stress-relief annealing, can be obtained by forming on its surface a forsterite film locally having regions, which have a thickness different from that of the remaining regions in the film, or locally having filmless regions which do not coat the steel sheet surface.

Abstract: A grain-oriented silicon steel sheet having high magnetic induction and low iron loss can be obtained by adhering uniformly at least one member selected from the group consisting of elements of Ge, Sn, Pb, As, Bi and Zn and compounds containing these elements to the surfaces of a silicon steel sheet before or after the decarburization annealing in a method for producing grain-oriented silicon steel sheets. According to this method, a hot rolled steel sheet is subjected to at least one cold rolling, the finally cold rolled steel sheet is subjected to a decarburization annealing, and the decarburized steel sheet is applied with an annealing separator consisting mainly of MgO and then subjected to a final annealing, or by carrying out the adhesion treatment of element in combination with a preliminary annealing before the decarburization annealing in the above described method, or by using the annealing separator further containing Bi or a Bi-containing compound in the above described method.

Abstract: A grain-oriented silicon steel sheet having excellent magnetic properties can be stably produced by adjusting properly the C content in a silicon steel to be used as a starting material depending upon the Si content in the steel, removing a proper amount of C from the steel during the course after the hot rolling and before the final cold rolling, and further carrying out the final cold rolling at a reduction rate of 40-80%.

Abstract: A grain-oriented electrical steel sheet having a very high magnetic induction is obtained by developing secondary recrystallized grains at a specifically limited secondary recrystallization temperature in a cold rolled silicon steel sheet containing substantially no antimony and aluminum and having a specifically limited low nitrogen content.