Study on The Effect of Shallow Cryogenic Treatment on Hardness and Microstructure of Gtawwelded Aa6061 Specimens

摘要

The Aluminium alloy AA 6061 loses its hardness significantly after Gas Tungsten Arc Welding (GTAW). The effect of post welded shallow cryogenic treatment (SCT) on hardness and micro structure of AA6061-T6 weldment is studied in this work. The GTAW welding was carried out with different heat inputs by varying the welding speed. The hardness and microstructure were evaluated for as-welded and post weld shallow cryogenic treated specimens. It is found that the hardness of the post welded SCT AA6061-T6 specimens increased significantly due to the reactivation precipitation sequence in the welded region.