Abstract: The invention produces a grain-oriented electrical steel sheet having a primary recrystallization structure in which Goss-oriented crystal grains and crystal grains having a coincidence orientation relationship to the Goss orientation are aligned in the rolling direction. It is characterized heating a slab containing, in mass %, C: 0.025 to 0.10%, Si: 2.5 to 4.5%, Mn: 0.03 to 0.55%, and Al: 0.007 to 0.040% to 1,100 to 1,450° C.

Abstract: The present invention provides high strength thick-gauge electric-resistance welded steel pipe excellent in hardenability, hot workability, and fatigue strength and a method of production of the same, that is, thick-gauge electric-resistance welded steel pipe containing, by mass %, C: 0.25 to 0.4%, Si: 0.01 to 0.50%, Mn: 0.8 to 1.5%, P: 0.05% or less, S: 0.05% or less, Al: 0.05% or less, Ti: 0.005 to 0.05%, B: 0.0005 to 0.01%, N: 0.001 to 0.05%, and a balance of Fe and unavoidable impurities, having a critical cooling rate Vc expressed by equation <1> of less than 30° C./s, and having a ratio of thickness t and outside diameter D, t/D, of over 0.15 to 0.30 in range: log Vc=2.94?0.75???<1> where, ?=2.7C+0.

Abstract: A steel pipe covered at its inside surface with a polyolefin superior in durability comprising a steel pipe galvanized at its inside surface and its outside surface with layers containing Al in 0.01 to 60 mass % and covered at its inside surface with a polyolefin pipe through a binder.

Abstract: A plastic lined steel pipe characterized by having an adhesive layer on an inner surface of a steel pipe, having a plastic layer on its further inner side, and having an initial shearing adhesion strength between the steel pipe and the plastic layer of 2.0 MPa or more, said steel pipe being a steel pipe given substrate treatment on its inner surface in advance, said substrate treatment comprising forming a phosphate chemical treatment coating treated for grain refinement, and preferably having an epoxy primer layer between the steel pipe and the adhesive layer.

Abstract: A plastic lined pipe with an end corrosive protection core used for snow removal, water supply, air-conditioning, firefighting, drainage, and other piping etc.

Abstract: An inexpensive method with good productivity, without coating of titanium metal, is necessary for satisfying the requirement for a long life of a heavy-duty anticorrosive steel material and in order to provide a heavy-duty anticorrosive coated steel material with excellent resistance against separation and corrosion. To respond to this demand, an oxygen-blocking layer is incorporated into the heavy-duty anticorrosive coating, for example, an organic resin sheet (film) capable of blocking the oxygen permeation is stacked or such an organic resin is painted on a conventional heavy-duty anticorrosive coating or a heavy-duty anticorrosive coating subjected to a chemical conversion treatment as the surface treatment.

Abstract: A steel pipe having a low yield ratio is provided. The steel pipe may contain, in mass, 0.01% to 0.20% C, 0.05% to 1.0% Si, 0.1% to 2.0% Mn and 0.001% to 0.05% Al, the microstructure of the steel pipe is composed of ferrite and pearlite, or ferrite and cementite, and the average size of the ferrite grains is at least 20 &mgr;m. The steel pipe may also contain, in mass, 0.03% to 0.20% C, 0.05% to 1.0% Si, 0.1% to 2.0% Mn, 0.001% to 0.05% Al, 0.01% to 0.5% Nb and 0.001% to 0.01% N, with the microstructure of the steel pipe being composed of ferrite and bainite, or ferrite, martensite and bainite, or ferrite and martensite.

Abstract: This invention provides a ferritic heat-resistant steel suitable for a pressure-resistant member to be used at a temperature of 400 to 550.degree. C. The ferritic heat-resistant steel having an excellent high temperature strength contains, in terms of wt %, 0.05 to 0.15% of C, 0.10 to 0.08% of Si, 0.20 to 1.5% of Mn, 0.5 to 1.5% of Cr, 0.10 to 1.15% of Mo, 0.005 to 0.30% of V, 0.005 to 0.05% of Nb, 0.0002 to 0.0050% of B, and if necessary, 0.005 to 0.05% of Ti and 0.4 to 1.0% of W, either alone or in combination, and having a structure comprising not greater than 15% of pro-eutectoid ferrite, in terms of a metallic structural area ratio, and the balance of bainite. The present invention provides also a process for producing a ferritic heat-resistant steel having an excellent high temperature strength, comprising tempering the steel having the composition at a temperature within the range 950 to 1,010.degree. C., and conducting tempering while keeping a T.P. value within the range of 18.50.times.10.sup.

Abstract: The present invention relates to a polyolefin-covered steel product and more particularly to a polyolefin-covered steel product, for use in a steel structure, having excellent impact resistance, flaw resistance and resistance to abrasion by littoral drift.The polyolefin-covered steel product comprises a steel product which has been subjected to surface treatment, and having laminated onto the treated surface, a modified polyolefin resin layer and a polyolefin resin layer, characterized in that the surface of the polyolefin resin layer is further covered with a fiber cloth to which a modified polyolefin resin has been laminated.