摘要:
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. The preferred Fe rich plating layer is a Fe-Zn alloy plating layer containing 20 to 80 wt % of Zn for corrosion resistance improvement. A Fe-Zn alloy plating layer containing 30 to 40 wt % of Zn meets both formability and corrosion resistance.
摘要:
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.
摘要翻译:一种包括制备总计约0.3-2.0重量%的Fe和Si的铝屑的方法; 熔化,然后调整材料组成以获得约3至10重量%的Mg含量或进一步含有至少一种元素Cu,Mn,Cr,Zr和Ti的组成,其量为0.02至0.5 重量% 对该材料进行铸造,热轧,冷轧和连续退火,得到拉伸强度为约31kgf / mm 2以上的铝合金板; 并施加润滑剂表面涂层以赋予不大于约0.11的摩擦系数。
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:
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:
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 method for manufacturing includes a polygonal shape closed structure part with a bent shape in the longitudinal direction only by press forming. The method uses two metal plates for manufacturing a curvilineal closed structure part and includes a press forming process of forming straight or bent folding lines in the longitudinal direction of the two metal plates at positions corresponding to a polygonal bent shape with a flange formed at least at one of the ends of the width direction of each plate, a process of forming a closed structure by laying the two metal plates to overlap each other flange to flange and end to end for ends without flanges and by welding the portions laid to overlap each other in the longitudinal direction of the metal plates, and a process of forming a polygonal shape closed structure having a bent shape in the longitudinal direction by holding both ends of the closed structure and by compressing it toward its central axis.
摘要:
A method for manufacturing a closed structure part has a closed section using a blank made from a metal plate by pressing the blank using a press forming die and fixing a pair of joint ends of the blank to each other, the method including a pre-forming step of processing the blank into an interim part having a closed section corresponding to the closed structure part, a closing step of, after the pre-forming step is completed, moving the joint ends of the interim part toward each other and urging, against one of the joint ends, a concave flange processing portion formed on one of a pair of press forming surfaces of the press forming die at the edge end adjacent to the other press forming surface, and a press joining step of, after the closing step is completed, further moving the press forming die in a pressing direction, bending the one of the joint ends using a pressing force applied from the flange processing portion so that the joint end overlaps the outer surface of the other join end and a latch flange portion for latching the other joint end is formed and, simultaneously, pressing the blank using the pair of press forming surfaces and press-forming outer portions of the pair of the joint ends of the blank into predetermined shapes.