An electric-resistance-welded stainless clad steel pipe or tube that is excellent in both the fracture property of the weld and the corrosion resistance of the pipe or tube inner surface as electric resistance welded without additional welding treatment such as weld overlaying after electric resistance welding is provided. An electric-resistance-welded stainless clad steel pipe or tube comprises: an outer layer of carbon steel or low-alloy steel; and an inner layer of austenitic stainless steel having a predetermined chemical composition, wherein a flatness value h/D in a 90 flattening test in accordance with JIS G 3445 is less than 0.3, and a pipe or tube inner surface has no crack in a sulfuric acid-copper sulfate corrosion test in accordance with ASTM A262-10, Practice E, where h is a flattening crack height (mm), and D is a pipe or tube outer diameter (mm).

An electric-resistance-welded stainless clad steel pipe or tube that is excellent in both the fracture property of the weld and the corrosion resistance of the pipe or tube inner surface as electric resistance welded without additional welding treatment such as weld overlaying after electric resistance welding is provided. An electric-resistance-welded stainless clad steel pipe or tube comprises: an outer layer of carbon steel or low-alloy steel; and an inner layer of austenitic stainless steel having a predetermined chemical composition, wherein a flatness value h/D in a 90 flattening test in accordance with JIS G 3445 is less than 0.3, and a pipe or tube inner surface has no crack in a sulfuric acid-copper sulfate corrosion test in accordance with ASTM A262-10, Practice E, where h is a flattening crack height (mm), and D is a pipe or tube outer diameter (mm).

A structural member is provided that includes a steel sheet with a tensile strength of 980 MPa or higher overlying another metal plate and joined thereto by welding, where a break initiating near a welded portion is less likely to be produced. A structural member (10, 10a, 10b, 10c) includes: a first member (1), the first member being a steel sheet with a tensile strength of 980 MPa or higher; a second member (2) overlying the first plate (1), the second member being a metal plate; a plurality of welded portions (3, 31, 32); a plurality of heat-affected zones (5, 51, 52) each formed to surround the corresponding one of the welded portions (3, 31, 32), the heat-affected zones having a Vickers hardness lower than that of the first member by 50 HV or more. A pair of edge sections (4) of the first member (1) are provided between adjacent heat-affected zones (5, 51, 52). The pair of edge sections (4) of the first member located between the adjacent heat-affected zones (5, 51, 52) extend to cross a line (LC1) linking the adjacent welded portions (3, 31, 32).

Art for spot welding able to suppress penetration of hydrogen, one of the factors behind delayed fracture, at the time of spot welding, that is, a spot welding method in which at one or both of the surfaces of the steel sheets becoming the facing surfaces of the overlaid steel sheets, a location where the steel sheets contact each other to form a contact part at the time of initial squeezing of the spot welding is worked in advance to form a plurality of lines running through the contact part and connected to the outside of the contact part and the spot welding is performed at the location of the contact part and also a steel sheet in which the plurality of lines are formed in advance at the location becoming a contact part when steel sheets contact each other at the time of initial squeezing in the spot welding.

Art for spot welding able to suppress penetration of hydrogen, one of the factors behind delayed fracture, at the time of spot welding, that is, a spot welding method in which at one or both of the surfaces of the steel sheets becoming the facing surfaces of the overlaid steel sheets, a location where the steel sheets contact each other to form a contact part at the time of initial squeezing of the spot welding is worked in advance to form a plurality of lines running through the contact part and connected to the outside of the contact part and the spot welding is performed at the location of the contact part and also a steel sheet in which the plurality of lines are formed in advance at the location becoming a contact part when steel sheets contact each other at the time of initial squeezing in the spot welding.

The present invention consists in a method of welding a nickel strength lug with a bronze connecting pin and a brass contact ring in an accelerometer sensor, the strength lug being interleaved between the connecting pin and the contact ring, the welding being effected electrically with the strength lug pressed simultaneously against the connecting pin and the contact ring. Before welding, the strength lug undergoes deformation of its external surface at least on each of two portions of the surface respectively facing the connecting pin and the contact ring, the surface deformation creating on each of the portions asperities intended to come into local contact with the connecting pin and the contact ring, respectively.

The present invention consists in a method of welding a nickel strength lug with a bronze connecting pin and a brass contact ring in an accelerometer sensor, the strength lug being interleaved between the connecting pin and the contact ring, the welding being effected electrically with the strength lug pressed simultaneously against the connecting pin and the contact ring. Before welding, the strength lug undergoes deformation of its external surface at least on each of two portions of the surface respectively facing the connecting pin and the contact ring, the surface deformation creating on each of the portions asperities intended to come into local contact with the connecting pin and the contact ring, respectively.

Provided is a joint component manufacturing method for reducing occurrence of burrs upon bonding between a first member having a hole and a second member having a shaft portion and firmly bonding both members. In the method for manufacturing a joint component 100, a hole-side weak press-fit portion 112 is formed at a hole 111 of a flat plate ring-shaped first member 110. Moreover, each of a shaft-side weak press-fit portion 122 and a shaft-side strong press-fit portion 124 is formed at a shaft portion 121 of a cylindrical second member 120. The hole-side weak press-fit portion 112 and the shaft-side weak press-fit portion 122 are defined by a first weak press-fit interference Lw1 formed thinner than a first strong press-fit interference Ls1. The shaft-side strong press-fit portion 124 is defined by a first strong press-fit interference Ls1 as the minimum necessary press-fit interference for electric resistance welding upon electric resistance welding between the hole 111 and the shaft portion 121.

An electric-resistance-welded stainless clad steel pipe or tube that is excellent in both the fracture property of the weld and the corrosion resistance of the pipe or tube inner surface as electric resistance welded without additional welding treatment such as weld overlaying after electric resistance welding is provided. An electric-resistance-welded stainless clad steel pipe or tube comprises: an outer layer of carbon steel or low-alloy steel; and an inner layer of austenitic stainless steel having a predetermined chemical composition, wherein a flatness value h/D in a 90 flattening test in accordance with JIS G 3445 is less than 0.3, and a pipe or tube inner surface has no crack in a sulfuric acid-copper sulfate corrosion test in accordance with ASTM A262-10, Practice E, where h is a flattening crack height (mm), and D is a pipe or tube outer diameter (mm).

An electric-resistance-welded stainless clad steel pipe or tube that is excellent in both the fracture property of the weld and the corrosion resistance of the pipe or tube inner surface as electric resistance welded without additional welding treatment such as weld overlaying after electric resistance welding is provided. An electric-resistance-welded stainless clad steel pipe or tube comprises: an outer layer of carbon steel or low-alloy steel; and an inner layer of austenitic stainless steel having a predetermined chemical composition, wherein a flatness value h/D in a 90 flattening test in accordance with JIS G 3445 is less than 0.3, and a pipe or tube inner surface has no crack in a sulfuric acid-copper sulfate corrosion test in accordance with ASTM A262-10, Practice E, where h is a flattening crack height (mm), and D is a pipe or tube outer diameter (mm).