선박용 스프링강의 피로수명에 미치는 쇼트피닝의 영향

Abstract

Alloy 625 is used widely in industrial applications such as aeronautical, aerospace, chemical, petrochemical and marine applications. Because of a good combination of yield strength, tensile strength, creep strength, excellent fabricability, weldability and good resistance to high temperature corrosion on prolonged exposure to aggressive environments. High quality weldments for this material are readily produced by commonly used processes. But all of processes are not applicable to this material by reason of unavailability of matching, position or suitable welding filler metals and fluxes may limit the choice of welding processes. Recently, the flux cored wire is developed and applied for the better productivity in several welding position including the vertical position. In this study, the weldability and weldment characteristics of Alloy 625 are evaluated in FCAW weld associated with the several shielding gases(80%Ar+20% CO2, 50%Ar+50% CO2, 100% CO2) in viewpoint of welding productivity. The results of the experimental study on corrosive characteristics of Alloy 625 are as follows; There is no remarkable difference among shielding gases, however they has a striking difference among corrosive solutions by results of distinguished density and time of corrosive solution. Generally, the shielding gases(80%Ar+20% CO2) was superior to the other gases on high temperature tensile and a low temperature impact. but all of the shield gases were making satisfactory results on corrosion test.