Author(s)

E. M. Basko, V. V. Larionov & V. N. Lazutin

Abstract

This report presents the results of spherical vessel investigation and laboratory research of physico-mechanical properties of steel and welded joints. Dynamics of corrosion-mechanical cracking of the vessel welded joints and brittle fracture resistance at low temperatures and dynamic forces have been given in the context of fracture mechanics. The major causes of corrosion-mechanical cracking of the vessel welded joints in the medium of liquid ammonia have been determined. The performance of works on stress deconcentration in the butt-welded joints on the inside of the wall being in contact with ammonia was demonstrated to be an effective method of increasing resistance to corrosion-mechanical cracking and brittle fracture. Keywords: spherical vessel, ammonia, pressure, cracks, defects, welded joints, life, cracking resistance, brittle fracture, dynamic stress. 1 Introduction Practice of application of the welded pressure vessels for storage of liquid ammonia demonstrated that corrosion-mechanical cracking (CMC) of welded joints is made possible in the course of their service. The action of extreme forces in cracking can result in brittle fracture of vessels at stresses that are substantially below the design values. This is associated both with the resulting dynamic effects and with dependence of cracking resistance characteristics and critical temperatures of vessel material brittleness on strain rate. In this connection when evaluating resistance to fracture of vessels for storage of ammonia on action of extreme forces it is necessary to take into account

Keywords

spherical vessel, ammonia, pressure, cracks, defects, welded joints, life, cracking resistance, brittle fracture, dynamic stress.