Abstract: A method for sintering Mn--Zn ferrite green compacts is provided which includes a first heating step of raising the temperature from room temperature to 600.degree. C. within a period from 30 minutes to 5 hours, a second heating step of raising the temperature from 600.degree. C. to the sintering temperature and holding the sintering temperature until the start of cooling within a period shorter than 10 hours, and a cooling step of lowering the temperature to 150.degree. C. within a period longer than 3 hours, with the total period of the three steps being shorter than 20 hours. This method permits the efficient production in a short time of Mn--Zn ferrites having good magnetic properties.

Abstract: A low power loss Mn-Zn ferrite consists essentially of Fe.sub.2 O.sub.3, MnO and ZnO at a given mole ratio and contains given amounts of SiO.sub.2, CaO, niobium oxide and titanium oxide or antimony oxide as trace additives. This ferrite is suitable as a transformer material for switched mode power supply.

Abstract: A method for producing an oxide useful as a starting material for making soft ferrites comprised mainly of iron, zinc and at least one metal selected from manganese, magnesium, nickel and copper is described. In the method, while chlorides of metals other than zinc are roasted for oxidation to produce a composite oxide, zinc oxide is added during the roasting. This method ensures addition of zinc oxide at high yield without use of zinc chloride having a high vapor pressure. The resultant oxide for ferrites has desired ratios of metal constituents and contains spinel ferrites which are intermediate products with zinc oxide being uniformly dispersed. The use of the starting oxide leads to omission of a calcination step and a powder mixing step in the production process of ferrites. Ferrites with good quality can be obtained by direct sintering.An alternative method using zinc chloride instead of zinc oxide is also described which can provide an equivalent oxide for making ferrites.

Abstract: A low power loss Mn-Zn ferrite consists essentially of Fe.sub.2 O.sub.3, MnO and ZnO at a given mole ratio and contains given amounts of SiO.sub.2, CaO, niobium oxide and titanium oxide or antimony oxide as trace additives. This ferrite is suitable as a transformer material for switched mode power supply.

Abstract: A method for producing a chemically colored stainless steel stock widely used as building material or the like is characterized in that a stainless steel stock is subjected to alternating current electrolysis or dipped and then subjected to an electrolytic treatment in a coloring electrolyte solution containing ions comprising a metal having a plurality of valence numbers, thereby producing colored stainless steel stocks having a variety of colors in a uniform color tone by a single solution/single step process. The continuous production apparatus of the invention can continuously manufacture colored stainless steel stocks with a variety of colors by a single solution/single step process in a commercial scale without any troublesome operation while affording the ease of control of color tone.

Abstract: An ultrasoft ferritic stainless steel having excellent stamping formability and corrosion resistance in use, which consists essentially of:about 0.002 to 0.03% by weight of carbon, about 0.01 to 0.30% by weight of silicon, about 0.01 to 1.5% by weight of manganese, about 0.003 to 0.04% by weight of phosphorus, about 0.001 to 0.15% by weight of sulfur, about 0.02 to 1.0% by weight of nickel, about 0.005 to 0.50% by weight of copper, about 0.01 to 0.6% by weight of molybdenum, about 11.5% to 20% by weight of chromium, about 0.005 to 0.03% by weight of nitrogen, about 0.005% to 0.20% by weight of aluminum, and the balance consisting of iron and conventional impurities, said ultrasoft steel having a Vickers hardness equal to about 140 or less.