Abstract: Provided is an electric-resistance-welded steel pipe or tube for hollow stabilizer where the formation of not only a ferrite decarburized layer but also a total decarburization layer can be suppressed even when heat treatment is performed in the air so that a hollow stabilizer having excellent fatigue resistance can be obtained. The electric-resistance-welded steel pipe or tube for hollow stabilizer has a predetermined chemical composition, and the depths of total decarburized layers on an inner surface and on an outer surface are 100 ?m or less.

Abstract: Provided is an electric-resistance-welded steel pipe or tube for hollow stabilizer excellent in corrosion fatigue resistance having: a chemical composition containing, in mass %, C: 0.15% or more and less than 0.20%, Si: 0.1% or more and 1.0% or less, Mn: 0.1% or more and 2.0% or less, P: 0.1% or less, S: 0.01% or less, Al: 0.01% or more and 0.10% or less, Ti: more than 0.05% and 0.1% or less, B: 0.0005% or more and 0.005% or less, Ca: 0.0001% or more and 0.0050% or less, and N: 0.0050% or less, with the balance being Fe and inevitable impurities; and a microstructure containing TiS and MnS particles which each have a particle size of 10 ?m or more, the TiS and MnS particles having a cleanliness of 0% or more and 0.1% or less as measured by a point counting method according to JIS G 0555.

Abstract: Provided is an electric resistance welded steel pipe or tube that develops no quench cracks despite having carbon content of 0.40% or more and has excellent fatigue strength. An electric resistance welded steel pipe or tube comprises: a chemical composition containing, in mass %, C: 0.40% to 0.55%, Si: 0.10% to 1.0%, Mn: 0.10% to 2.0%, P: 0.10% or less, S: 0.010% or less, Al: 0.010% to 0.100%, Cr: 0.05% to 0.30%, Ti: 0.010% to 0.050%, B: 0.0005% to 0.0030%, Ca: 0.0001% to 0.0050%, and N: 0.0005% to 0.0050%, with a balance consisting of Fe and inevitable impurities; and a ferrite decarburized layer at each of an outer surface and an inner surface, the ferrite decarburized layer having a depth of 20 ?m to 50 ?m from the surface.