船舶用 構造 鎔接材의 腐蝕 및 疲勞破壞 强度 硏究

Abstract

There is a strong probability that welding structure, which is particularly used for ship-building, produces defect not in its base metal but in its welding part. This Study has executed digestion of welding agents upon 3 ways of welding such as SMAW, FCAW and SAW in the solution of 3.5% NaCl and 6% FeCl3 for 60 days, 90 days and 180 days, respectively to make quantitative analysis of the corrosion and fatigue characteristics of the weldment and, consequently, grasped for the tendency by the three welding methods through investigating its Corrosion Weight Loss and Corrosion Potential characteristics, and executed digesting the said three welding agents in two solutions for 90 days and carried out Corrosion Fatigue Test for them in the air and, thereby, made enabled to predict fatigue life and strength by drawing out S-N curve. As the result of this test, the mechanical property of the welding agents was getting lower than the base metal and, whereas, showed that SMAW is, in general, more excellent than FCAW and SAW in corrosion and fatigue strength. This study, of course, needs additional review through investigating its more concreted test plan and inquiry and, on the one hand, it is suggestive from the test result of this study that auto welding device to make best application of manual welding conditions be developed for the purpose of raising up the effect of auto welding for the areas, which need special attention to their corrosion & fatigue strength, like ship structure.