Statistical evaluation of low cycle durability for corrosion and heat-resistant steels welded joints materials at room and elevated temperature

Abstract

In this work low cycle fatigue durability dependenceupon mechanical characteristics for corrosion andheat-resistant steels and their weld metals used in nuclearengineering was analyzed. The results of 55 corrosion andheat-resistant steels, 36 their weld metals at room and 46corrosion and heat-resistant steels at elevated temperaturesare obtained in the laboratories of Kaunas University ofTechnology and in Slovakia, Russia, and Hungary. Parametersof low cycle curves according plastic strain Cp, mpand elastic strain Ce , me for these steels and their weldmetals at room and elevated temperatures are analyzed.Statistical analysis confirmed, that fracture characteristicsand modified plasticity are independent values, they havenormal distribution and durability has linear correlationwith the modified plasticity (σ u σ y )Z . Analytical dependencesof constants Ce, me, Cp, mp on modified plasticityare proposed for these materials at room and elevatedtemperatures. The comparison of calculated and experimentaldurability results showed, that the proposed analyticaldependencies may be used for preliminary estimationof low cycle durability of the investigated materials.