Abstract: The present invention provides an ohmic heating-type exhaust gas purification catalyst system. The ohmic heating-type exhaust gas purification catalyst system is configured to perform, based on information of temperature of a catalyst bed input from a temperature detector of an ohmic heating-type exhaust gas purification device, electric current pass control including controls of (1) causing an electric current to pass through a pair of electrodes when the temperature of the catalyst bed is equal to or lower than a first threshold temperature T1 set in a range of 350±25° C., (2) not causing an electric current to pass through the pair of electrodes when the temperature of the catalyst bed exceeds the first threshold temperature T1 and is equal to or lower than a second threshold temperature T2 set in a range of 450±25° C.

Abstract: A part or jig of a metal for a gas carburizing furnace has an Al diffusion layer which has an Al content of 10 to 50 wt % in the surface portion of the part or jig, the Al diffusion layer being formed by carrying out the calorizing treatment.

Abstract: A reusable weld backing capable of withstanding long use, which is held against the underside of a workpiece to provide weld-metal support in full penetration welding, the weld backing comprising a substrate made from copper or a copper alloy; and a copper-aluminum alloy layer containing 9 to 23% by weight of aluminum and formed at least on the surface of the substrate, the surface being on the side which faces a weld zone.