Abstract: A method of designing a ferritic iron-base alloy having excellent characteristics according not to the conventional trial-and-error technique but to a theoretical method, and a ferritic heat-resistant steel for use as the material of turbines and boilers usable even in an ultrasupercritical pressure power plant. Specifically, the d-electron orbital energy level (Md) and the bond order (Bo) with respect to iron (Fe) of each alloying element of a body-centered cubic iron-base alloy are determined by the Dv-X.alpha. cluster method, and the type and quantity of each element to be added to the alloy are determined in such a manner that the average Bo value and average Md value represented respectively by the following equations:average Bo value=.SIGMA.Xi.(Bo)i 1average Md value=.SIGMA.Xi.

Abstract: The present invention provides a process for efficiently dephosphorizing, dephosphorizing and decarbonizing, or desulfurizing, dephosphorizing and decarbonizing a hot metal in a converter. The amount of flux to be charged and the amount of bottom-blown gas are adjusted so that the bottom-blowing agitation power and the CaO/SiO.sub.2 ratio subsequent to the treatment become at least 0.1 kW/ton and from 0.7 to 2.5, respectively and the hot metal temperature at the treatment end point becomes from 1,200.degree. to 1,450.degree. C. Furthermore, the operation of the process is controlled so that the sum of a T.Fe concentration and a MnO concentration in the slag subsequent to the treatment becomes from 10 to 35% by weight by adjusting the top-blown oxygen feed rate, the flow rate of bottom-blown gas or the top-blowing lance height.

Abstract: A method for estimating the inclusion content of a metal, the method involving three steps. The first step is to section the metal to create an exposed inner surface of the metal. The second step is to measure the reflectance of the exposed inner surface of the metal. The third step is to estimate the inclusion content of the metal from the reflectance. When a physical property of the metal, such as tensile strength, elongation or impact strength, is related to the inclusion content of the metal, then the physical property can be estimated from the reflectance of the exposed inner surface of the metal.

Abstract: In an apparatus for continuously annealing a steel strip after cold rolling, stable operation of the annealing apparatus can be obtained by preventing slippage of bridle rolls and hearth rolls. The diameter D of a bridle roll is set so that a surface pressure p defined by an equation p=h(.sigma..sub.1 +.sigma..sub.2)/D can be 10 kPa (kilopascal) or more, wherein the unit tension of a steel strip at the inlet side of the bridle roll and hearth rolls of the apparatus is .sigma..sub.1, the unit tension at the outlet side is .sigma..sub.2, the thickness of the steel strip is h and the diameter of the bridle roll is D.

Abstract: A method and apparatus are provided for producing rods having a desired tensile strength from a rod manufacturing process set to an optimal operating condition. Initially, the rod manufacturing process is set in an optimal condition to produce rods at a maximum rate, while optimizing the mechanical properties therein. Raw materials are melted and a "heat of steel" representing one lot is poured into a ladle which is sampled to determine its chemical composition. The percentage content of each element is utilized within an empirical model modeling the rod manufacturing process to predict the tensile strength of rods. The empirical model is again utilized to determine the amount by which a control element must be varied to adjust the predicted tensile strength to the desired tensile strength. The control element represents an element, such as, carbon which significantly impacts the tensile strength of the rod.

Abstract: A device (100) for the heat treatment of at least one metal wire (1), chaterized by passing the wire (1) within at least one pair of thermal transfer plates (2, 2a, 2b) between two grooves (8, 8a, 8b) made in the two plates (2, 2a, 2b) of each of said pairs, the distance (E) between the plates being variable, the wire (1) being directly in contact with a gas (11) which is practically without forced ventilation and is disposed between the grooves (8, 8a, 8b).

Abstract: A method of manufacturing a low-core-loss oriented electrical steel sheet. Thread-like grooves are formed in a cold-rolled grain oriented electrical steel sheet having a final thickness of about 0.27 mm or less in a direction within the range of about 30.degree. from the direction perpendicular to the rolling direction. The grooves and sheet satisfy the equationlog d.gtoreq.0.6 Ra+0.4where d is the groove depth (.mu.m), and Ra is the mean surface roughness of the steel sheet cold-rolled to final gauge. The steel sheet is thereafter decarburization annealed and final texture annealed.

Abstract: It is an object to provide a process for manufacturing galvannealed steel sheets having high anti-powdering property as required when they are press formed, and stabilized frictional properties in a coil. Steel sheets are plated in a bath having a low aluminum content, while they have, when entering the bath, a low temperature as defined in relation to the aluminum content of the bath, so that an alloying reaction may be prevented. Then, the sheets are heated for alloying in a high-frequency induction heating furnace so that the sheets leaving the furnace may have a temperature of from over 495.degree. C. to 520.degree. C. to yield galvannealed consisting mainly of a .delta..sub.1 phase. An iron or iron-alloy top coating having an appropriate iron content can be applied onto the plated steel surface to improve its paintability.

Abstract: Method of manufacturing a grain oriented silicon steel sheet. An annealing separating agent mainly composed of MgO is coated on a surface of a decarburized silicon steel sheet. The silicon steel sheet is subjected to secondary recrystallization annealing and then purification annealing. The annealing separating agent contains Ti oxide or a Ti compound which can be oxidized by heating. The purification annealing is conducted in steps. A non-oxidizing atmosphere having a high nitrogen concentration is present in one step. A hydrogen atmosphere having a low nitrogen concentration is present in a subsequent step.

Abstract: An Fe-Ni alloy sheet for a shadow mask, which consists essentially of:nickel: from 34 to 38 wt. %,silicon: from 0.01 to 0.15 wt. %,manganese: from 0.01 to 1.00 wt. %, andthe balance being iron and incidental impurities.The surface portion of the alloy sheet has a silicon (Si) segregation rate, as expressed by the following formula, of up to 10%: ##EQU1## and a center-line mean roughness (Ra) of the alloy sheet satisfies the following formula:0.3 .mu.m<.ltoreq.Ra .ltoreq.0.7 .mu.m.The above-mentioned Fe-Ni alloy sheet is manufactured by preparing an Fe-Ni alloy sheet having the chemical composition and the silicon segregation rate as described above, and imparting a center-line mean roughness (Ra) which satisfies the above-mentioned formula onto the both surfaces of the alloy sheet by means of a pair of dull rolls during the final rolling of the alloy sheet for said preparation.

Abstract: An Fe-Ni alloy sheet for a shadow mask, which consists essentially of:nickel: from 34 to 38 wt. %,silicon: from 0.01 to 0.15 wt. %,manganese: from 0.01 to 1.00 wt. %, andthe balance being iron and incidental impurities;the surface portion of the alloy sheet having a silicon (si) segregation rate, as expressed by the following formula, of up to 10%: ##EQU1## and the alloy sheet having a surface roughness which satisfies all the following formulae (1) to (3):0.3 .mu.m.ltoreq.Ra.ltoreq.0.8 .mu.m (1)where, Ra: center-line mean roughness;3.ltoreq.Rkr.ltoreq.