Cf CORROSION-FATIGUE CRACK GROWTH BEHAVIOR OF PIPINGAND REACTOR PRESSURE VESSEL STEELS

摘要

As test materials, the nuclear-grade steels were selected such as carbon steel 20 (similar to steel С1020)and 22К (similar to steels К01701 and К02401), alloyed steel 15Х2НМФА (similar to steel А543), including themetal of the welded joint, as well as stainless steel 08Х18Н12Т (similar to steel 321) with the welded joint. Theexperimental investigations of the regularities of the crack propagation in steels were carried out on two types ofspecimens: compact tension and flat bending specimens. The report describes special experimental equipment, testmethods and results. The experimental complex includes test facilities with the forced circulation and naturalcirculation loops, as well as 100°C aqueous medium test facilities using for comparing the results. The effect ofbasic load variables (load ratio and frequency), temperature (from 80°C to 280°C) and aqueous medium chemicalcomposition on the nature of fatigue crack propagation was studied. The selection of the aqueous medium wasdefined by the conventional water-chemistry conditions of РWR and ВWR with due account for the solution pHvalue and the electrode potential at the propagating crack tip. The comparison is given of the test results with theeffective normative specifications. Based on the analysis of test results the generalized characteristics of thecorrosion crack resistance of various structural steels are given.