摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
The number of sub-parts of a closed structure part and the number of steps for manufacturing the closed structure part can be reduced and, therefore, the closed structure part can be efficiently manufactured. In a hemming press step, a punch is further lowered, and a pair of flange portions is inserted into a slit clearance. Hemming prongs are bent and each of the hemming prongs sandwiches the flange portion. The flange portion, which is one of the two flange portions, is joined to the other flange portion. At the same time, a pair of press forming surfaces of the punch presses a metal plate and performs press-forming on a pair of shoulder portions of a blank into a predetermined shape. The flange portion can be fixed to the other flange portion using the hemming prongs. The pair of shoulder portions of the blank can be press-formed into the predetermined shape.
摘要:
A laminated piezoelectric device obtained by alternately laminating the piezoelectric layers containing Pb and the conducting layers containing palladium as a conducting component, wherein the piezoelectric layer formed between the two conducting layers has layer regions where Pb and Pd are mixed together in the interfacial portions thereof relative to the conducting layers, the layer regions having a thickness of not larger than 3% of the thickness of the piezoelectric layer. The laminated piezoelectric device is formed by co-firing the Pb-containing piezoelectric layers and the palladium (Pd)-containing layers, the piezoelectric layers therein having a large insulation resistance and good piezoelectric characteristics.
摘要:
The steel pipe has a structure composed mainly of ferrite or ferrite plus pearlite or ferrite plus cementite. The steel pipe is characterized by grain size not greater than 3 &mgr;m, preferably not greater than 1 &mgr;m, elongation greater than 20%, tensile strength (TS:MPa) and elongation (E1:%) whose product is greater than 10000, and percent ductile fracture greater than 95%, preferably 100%, measured by Charpy impact test on an actual pipe at −100° C. The structure is characterized by C: 0.005-0.03%, Si: 0.01-3.0%, Mn: 0.01-2.0%, and Al: 0.001-0.10% on a weight basis, and is composed of ferrite or ferrite and a secondary phase, with ferrite grains being not greater than 3 &mgr;m and the secondary phase having an areal ratio not more than 30%. A steel pipe stock having the above-mentioned composition is heated at a temperature of (Ac1+50° C.) to 400° C. and subsequently reduced at a rolling temperature of (Ac1+50° C.) to 400° C. such that the cumulative reduction of diameter is greater than 20%. The reducing is preferably performed such that at least one of rolling passes reduces the diameter by more than 6% per pass. The steel pipe will have high ductility and high strength and will be superior in toughness and stress corrosion cracking resistance, if the content of C, Si, Mn, and other alloying elements is limited low and reducing is performed at the temperature specified above. The resulting steel pipe has good fatigue resistance and is suitable for use as line pipe.
摘要:
A high strength steel sheet for automobiles which exhibits excellent press-formability strength against impact resistance at a high strain rate is hot rolled under specific conditions, or is cold rolled from hot rolled sheet which is prepared under conventional conditions, with the cold rolled steel being annealed under specific conditions. The steel sheet comprises 0.010-0.10 wt % of C, not greater than 1.50 wt % of Si, 0.50-3.00 wt % of Mn, not greater than 0.010 wt % of S and 0.01-0.1 wt % of Al, and one kind or two kinds selected from 0.05-0.15 wt % of P and 0.5-1.5 wt % of Cr, and the balance being Fe and inevitable impurities and having a structure mainly composed of 2-30 vol % of martensite phase and a ferrite phase containing a solution C not greater than 0.0010 wt %.
摘要:
The number of sub-parts of a closed structure part and the number of steps for manufacturing the closed structure part can be reduced and, therefore, the closed structure part can be efficiently manufactured. In a hemming press step, a punch is further lowered, and a pair of flange portions is inserted into a slit clearance. Hemming prongs are bent and each of the hemming prongs sandwiches the flange portion. The flange portion, which is one of the two flange portions, is joined to the other flange portion. At the same time, a pair of press forming surfaces of the punch presses a metal plate and performs press-forming on a pair of shoulder portions of a blank into a predetermined shape. The flange portion can be fixed to the other flange portion using the hemming prongs. The pair of shoulder portions of the blank can be press-formed into the predetermined shape.