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 snow melting panel has a piping arrangement that includes straight pipe lines and U-shaped bend sections is provided. The panel can be sized such that the parallel length of the straight pipe lines is 300 to 5000 mm, and the perpendicular span of the straight pipe lines is 100 to 4000 mm. The piping arrangement may have a hot-dip galvanized layer or a highly corrosion resistant galvanized layer formed or provided only on the outer surface of the piping arrangement. For example, the gap between adjacent pipes in the straight pipe lines is 100 to 300 mm. In addition, the straight pipe lines and the bend sections can be made from a single long pipe. The piping arrangement may be made from a steel pipe with a silicon content of less than 0.05 wt %, or not less than 0.15 wt % and not more than 0.20 wt %.

Abstract: A snow melting panel has a piping arrangement that includes straight pipe lines and U-shaped bend sections is provided. The panel can be sized such that the parallel length of the straight pipe lines is 300 to 5000 mm, and the perpendicular span of the straight pipe lines is 100 to 4000 mm. The piping arrangement may have a hot-dip galvanized layer or a highly corrosion resistant galvanized layer formed or provided only on the outer surface of the piping arrangement. For example, the gap between adjacent pipes in the straight pipe lines is 100 to 300 mm. In addition, the straight pipe lines and the bend sections can be made from a single long pipe. The piping arrangement may be made from a steel pipe with a silicon content of less than 0.05 wt %, or not less than 0.15 wt % and not more than 0.20 wt %.