Abstract: In a process for the preparation of oriented electrical steel sheet having a high magnetic flux density a primary recrystallization annealed steel sheet is nitrided for a short period of time in a temperature range of 800.degree. C. or less whereby growth of crystal grains does not substantially occur. The nitrided sheet is held at a temperature range of 700.degree. C. to 800.degree. C. for at least four hours during temperature raising to final annealing temperature whereby nitride formed by the nitriding dissolves and re-precipitates allowing the nitride to transform to a thermally stable nitride containing aluminium.

Abstract: A non-magnetic material for a magnetic head and a magnetic head produced with the use of such material. For improving the head efficiency and resistance against partial abrasion, the guard piece 11 is mainly composed of CaO, TiO.sub.2 and NiO, with the molar mixing ratio CaO/TiO.sub.2 being 30/70 to 50/50 and the NiO content being 5 to 30 mol %. The head efficiency may be improved, while the partial abrasion may be decreased and the service life of magnetic head may be improved sufficiently.

Abstract: In a continuously cast piece of austenitic stainless steel having a large amount of Mo, segregation of alloy elements such as Mo and Cr is caused at the center part in the thickness direction of the slab, and the .sigma.-phase is precipitated during the step of cooling the cast piece. When a heavy plate or hot coil is prepared from this cast piece as the starting material, cracking occurs in the hot-working step and the corrosion resistance of the final product is degraded. According to the present invention, at the cast piece-forming step, the super-heating degree of the molten steel is controlled to at least 25.degree. C., whereby the equiaxed zone ratio is controlled to below 25%. When the heating times at the soaking and hot rolling treatments and the conditions for annealing the obtained steel sheet are controlled, the pitting resistance of the steel plate is greatly improved and cracking is prevented at the hot-working step.