Structure and Mechanical Properties of Welded Joints of Large Steel Forgings for Nuclear Power Plants of MIR 1200 Type

Abstract

The paper deals with research, development and verification of production technology of selected welded joints for pressure vessels located in primary circuit of nuclear power plants type MIR 1200. Effects of various welding technologies on mechanical and fracture properties were studied. Four types of weld joints made of 10GN2MFA steel grade were prepared for experimental programme consisted of testing of conventional mechanical (tensile and impact tests) as well as fracture toughness and low-cycle fatigue tests and also stress corrosion cracking test in water environment. Effect of elevated operating temperature on material properties was evaluated, too.