Pengaruh Lingkungan Las terhadap Kekuatan Impak Sambungan Las Aluminum AA1100

Abstract

Due to lightweight and strong, aluminum is often applied to the car bodies of an automotive and high-speed train. Welding is the main manufacturing process for these structures. Environmental conditions in welding, especially airflow velocity, humidity, and temperature, significantly affect the impact property of aluminum alloy weld joints. In this work, the welding environment is controlled by creating an insulating welding room where the airflow velocity, humidity, and temperature of the welding environment can be adjusted to obtain an ideal welding environment. The variation of welding environment conditions used was the temperature of 17°C, 22°C, and 27°C; relative humidity of 64%, 68%, and 72% and airflow velocity of 1.1m/s, 1.6m/s, and 2.1m/s. The results showed that the lower the welding environment temperature, the more toughness decreased. The lower the flow rate and the relative humidity of the surrounding air, the tougher it is. Air humidity contains a lot of water vapor (hydrogen) which can cause porosity. The low temperature of the welding chamber results in a shorter freezing time of the weld metal, resulting in cracking and porosity in the weld metal. The ambient airflow velocity interferes with the shielding gas function so that the outside air can be contaminated in the weld metal. The best welding environmental conditions will be achieved if the airflow velocity is below 1.1 m / s, the relative humidity is below 64% and the ambient temperature is 27°C.

Effect of Air Humidity in MIG Welded Joints on Tensile Strength and Impact Strength of Aluminum 5052

“…Berdasarkan Gambar 12 dapat dilihat bahwa kekuatan impact tertinggi yaitu pada spesimen Y yang memiliki nilai impact 89.42 J/mm², dan kekuatan impact terendah yaitu pada material Z dengan nilai impact 80.10 J/mm². Hasil ini senada dengan yang ditemukan oleh [14], yaitu Kelembaban relatif lingkungan pengelasan berpengaruh pada hasil pengelasan. Semakin tinggi kelembaban relatif lingkungan, hasil kekuatan impak semakin menurun.…”