REGULARITIES OF STRAIN AND FAILURE IN THE METAL OF WELDED JOINTS OF CONSTRUCTION STEEL AT ELEVATED TEMPERATURES UNDER THE CONDITIONS OF STATIC AND LOW-CYCLE LOADING. COMMUNICATION 1. STRAIN RESISTANCE.

Elevated temperatures (to 873 K) are considered for their effect on static and low cycle rigid deformation resistance of particular zones in welded joints of ESR 09G2S steel. It is shown that the static characteristics of strength and ductility of the welded joints metal increase 2-6 times and have a complex temperature dependence within the studied temperature range. It is established that cyclic elastoplastic properties of the studied zones of the welded joint depend on the test temperature: cyclic stability of the basic metal and cyclic loss of strength of the weld and heat affected zone metal at 293 K is replaced for cyclic hardening of all zones of the welded joint within the temperature range of dynamic strain aging 473-672 K while at the temperature above 825 K initial cyclic deformation properties are recovered.