Abstract: A method including preparing an aluminum scrap containing a total of about 0.3 to 2.0 wt % of Fe and Si; melting and then adjusting the material composition so as to attain an Mg content of about 3 to 10 wt % or a composition further containing at least one of the elements Cu, Mn, Cr, Zr and Ti, each in the amount of 0.02 to 0.5 wt %; subjecting the material to casting, hot rolling, cold rolling and continuous annealing to obtain an aluminum alloy sheet having a tensile strength of about 31 kgf/mm.sup.2 or more; and applying a lubricant surface coating to impart a coefficient of friction of not more than about 0.11.

Abstract: In a hot-dip zinc-coated steel sheet exhibiting excellent press die sliding characteristics and obtained by performing a molten galvanization and then skin pass rolling on a surface of the steel sheet, a galvanized layer has a three-dimensional average surface roughness ranging from 0.7 .mu.m to 1.4 .mu.m, and a skewness (S) of the amplitude probability distribution of the surface roughness, which is defined by the following equation (1), ranging from 0.1 to -0.3:S=.mu..sub.3 /.sigma..sup.3 (1)where.mu..sub.3 : Three-dimensional moment of the amplitude probability density.sigma.: Standard deviation of the amplitude probability density.

Abstract: The invention provides an aluminum alloy sheet having improved formability, an elongation of at least 30%, a sliding frictional resistance of up to 0.13 and minimized surface pressure dependency of sliding frictional resistance, comprising an aluminum alloy substrate containing at least 4 wt % of Mg and a Fe rich plating layer on a surface thereof in a coating weight of 1 to 50 g/m.sup.2. Also provided is a bake hardenable, surface treated aluminum alloy sheet having improved formability, an elongation of at least 25%, a sliding frictional resistance of up to 0.13 and minimized surface pressure dependency of sliding frictional resistance, comprising a bake hardenable aluminum alloy substrate containing Mg and Si in an amount of at least 0.4 wt % calculated as Mg.sub.2 Si and a Fe rich plating layer on a surface thereof in coating weight of 1 to 50 g/m.sup.2. By forming a zincate layer as an undercoat below the Fe rich plating layer, the plating adhesion is further improved.

Abstract: A process and an equipment for micro-pattern forming on the surface of a rolling roll, and a metallic thin sheet and preparation thereof by transferring a micro-pattern on the surface by use of the roll are provided. Such a rolling roll can be attained by a method wherein resin film mixed with optical absorbing agent is formed on the surface, a Q switch YAG laser having an output of 5 to 100W is applied to make a marking on this resin film, a part of the coated film is removed in strict accordance with the pattern, then an etching process is applied to the roll surface. The metallic thin sheet skin pass rolled by this roll is used as a car panel and is superior in pressworkability and sharpness of reflections.

Abstract: A slab is successively fed between periodically moving press tools to reduce the slab in a widthwise direction. In this method, the leading and tail end portions of a given length in the slab are reduced at a reduced width wider than that of remaining steady portion.

Abstract: A steel cord comprising at least 10 metal filaments and having an elongation of 0.015-0.045% under a load of 0.5 kgf, an elongation of 0.025-0.060% under a load 1 kgf, and an elongation of 0.060-0.114% under a load of 4 kgf, assuming that the elongation under a load of 0.05 kgf is 0%, has a soft twist construction and is suitable to be used in the carcass of a radial tire for truck and bus.

Abstract: A continuous annealing apparatus for metal strips comprises cylindrical rolls each arranged at a location immediately before the metal strip passes about a hearth roll in a high temperature heat-treatment region of the apparatus. An axis of the cylindrical roll is finely tilted relative to the hearth roll within 0.15 degree in directions compensating for shifted distances of the metal strip on the hearth roll in response to every 50 mm shift of the strip, thereby preventing meandering and buckling of the metal strip caused by the hearth rolls.

Abstract: In the operation of a continuous-process annealing furnace for a steel strip of a continuous length which is guided through the high-temperature zones of the furnace by the upper and lower hearth rolls in an alternate up and down vertical movement, each of the hearth rolls having an end-tapered or crowned configuration to correct the meandering of the running strip, each of the hearth rolls is coupled with one or a plural number of straightly cylindrical auxiliary rolls in contact with the strip at a position close to the hearth roll. By virtue of the installation of the auxiliary rolls, the phenomenon of wrinkling or buckling in the steel strip can be effectively prevented without causing meandering and the effect is more remarkable when specific relationships are held among the values of the diameters of the hearth roll and auxiliary roll and the position of the auxiliary roll relative to the hearth roll.