Microstructure and Mechanical Properties in the Friction Stir Welded C70600 Alloy

다국어 초록 (Multilingual Abstract)

A friction stir welded (FSW-ed) C70600 alloy plate was partially welded to other C70600 alloy plate by the gas tungsten arc welding (GTAW). First, FSW was performed on the C70600 alloy by 2-steps (on the top and the bottom). The ultimate tensile strength after FSW was average 317MPa very close to that (average 324MPa) of GTAW-ed C70600 joint. The bending test results after FSW varied by the welding condition. Case A failed the bending test according to the ASME code (ASME Sec. Ⅸ) at the face bending because of relatively lower heat input (rotation speed/traveling speed was 600rpm / 200mm/min) while Case B (higher heat input; rotation speed/traveling speed was 1200rpm / 200mm/min) met the requirements. There were characteristic microstructures such as black-arc-arrays of the oxides in the FSW stir zone (SZ) and the micro-pores in the boundary between FSW-SZ and GTAW weld metal (WM). The former was originated from the crushed and stirred oxides which pre-existed on the base metal surface. The latter could result from re-gasified O2 gas formed by Cu oxides melted at the boundary between FSW-SZ and GTAW-WM.

목차 (Table of Contents)

• Abstract
• 1. Introduction
• 2. Experimental Procedure
• 3. Result and Discussion
• 4. Summary
• References