Behavior and susceptibility to stress corrosion cracking of a nickel‐based alloy in superheated steam and supercritical water

Abstract

Stress corrosion cracking (SCC) behavior of Alloy 617 was studied to evaluate its suitability for Generation IV supercritical water reactor concept. A series of slow strain rate tensile (SSRT) tests at a constant strain rate of 5 × 10−7 s−1 were carried out in superheated steam and supercritical water over a pressure range of 0.1–25 MPa at 650 °C. SSRT test in dry N2 gas was also performed to compare the results in non‐corrosive environment with corrosive medium environment. Intergranular cracks were observed for all specimens regardless of the test environment. Alloy 617 showed susceptibility to SCC at the tested experimental conditions. The dominance of intergranular SCC was observed on the gage surface and fracture surface by using scanning electron microscope analysis. The effect of varying environmental conditions on SCC susceptibility is further discussed.

Microstructure and Electrochemical Corrosion Behaviors of Laser‐Cladded 2205 Duplex Stainless Steel

“…To enhance the corrosion resistance of carbon steel, the laser cladding technique can be used to form an anticorrosion coating on the carbon steel surface. Stainless steels, nickel‐based alloys, and cobalt‐based alloys have been widely used in the petroleum, chemical, aircraft, and nuclear power industries due to their excellent mechanical properties and corrosion resistance . Of these materials, stainless steel coatings are the most economical in common service environments.…”

Effect of medium and pressure on stress corrosion cracking susceptibility of a nickel-based alloy

“…SSRT experiments were conducted on the self-developed dynamic SCW stress corrosion test platform. The details of principle and structure of the platform can be found in the work of Khan et al 38,39 After primary and secondary pre-heating, water was introduced into the autoclave (2.83 l) and subsequently cooled to room temperature through air cooling and water cooling, respectively. The function of autoclave was to finally reach and maintain temperature and pressure at desired values.…”

Stress corrosion cracking susceptibility of a new nickel‐based alloy in different environments

“…Figure 3 shows the schematic diagram of the test bench. [24,25] This test bench consists of the water circulation circuit, servo unit, and data acquisition…”

“…As the F I G U R E 3 Schematic diagram of supercritical water stress corrosion cracking susceptibility test bench. [24,25] Abbreviations: C-2, C-HRA-2; SCW, supercritical water; SHS, superheated steam.…”