ELECTRIC RESISTANCE WELDED STEEL TUBE FOR HIGH-STRENGTH HOLLOW STABILIZER, METHOD FOR MANUFACTURING ELECTRIC RESISTANCE WELDED STEEL TUBE FOR HIGH-STRENGTH HOLLOW STABILIZER, HIGH-STRENGTH HOLLOW STABILIZER, AND METHOD FOR MANUFACTURING HIGH-STRENGTH HOLLOW STABILIZER

摘要

Provided are an electric resistance welded steel tube for a high-strength hollow stabilizer having excellent corrosion fatigue resistance characteristics, a method for manufacturing an electric resistance welded steel tube for a high-strength hollow stabilizer, a high-strength hollow stabilizer, and a method for manufacturing a high-strength hollow stabilizer. An electric resistance welded steel tube in which an electric resistance welded steel tube obtained by electric resistance welding a steel plate and forming a tube is further subjected to rolling reduction while hot, the electric resistance welded steel tube having a composition including, in terms of mass%, 0.20-0.40% C, 0.1-1.0% Si, 0.1-2.0% Mn, 0.01-0.10% Al, 0.01-0.5% Cr, 0.01-0.05% Ti, 0.0005-0.005% B, 0.0001-0.0050% Ca, and 0.0050% or less of N, the remainder comprising Fe and unavoidable impurities, and a metallographic structure in which TiS particles having a particle diameter of 10 µm or greater and MnS particles having a particle diameter of 10 µm or greater are each reduced to 0.1% or less by cleanliness. Through this configuration, an electric resistance welded steel tube is obtained which exhibits high strength (high hardness), the hardness thereof after cold forming and quenching/tempering being 400 HV to less than 550 HV in terms of Vickers hardness, the average particle diameter of prior austenite grains being 50 µm or less, and the electric resistance welded steel tube having excellent fatigue resistance characteristics (corrosion fatigue resistance) for a hollow stabilizer even in a corrosive environment.