Properties of Longitudinal Welded Steel Pipes for Piled Foundations Built under Cryolithic Zone Conditions

Abstract

The mechanical properties of the base metal and the welded joints are estimated during tension, impact bending, drop weight tearing, static bending, flattening tests, and the Vickers hardness and the residual tangential stresses in them are determined for the longitudinal welded pipes 219–1020 mm in diameter and 8–12 mm in wall thickness manufactured by the AO Vyksunskii Metallurgical Plant. The hardness distribution over the pipe perimeter and the cross section is uniform and the cracking resistance of the pipes at negative temperatures up to –60°C is high. Local heat treatment of the welded seam and high-temperature tempering of the entire pipe ensure a high strength and high cold resistance of the pipes. The longitudinal pipes subjected to local and bulk heat treatment can be used like seamless pipes and as piles for the bases of buildings and structures erected in the cryolithic zone.