The Effect of Ferrite Content on Mechanical Properties and Corrosion Behaviour of Austenitic Stainless Steel 308L Weld Metal

摘要

Ferrite is well known as a beneficial phase that can prevent hot cracking phenomena and act as strengthening phase in austenitic stainless steel weld metal. This paper investigated mechanical and corrosion behaviour of austenitic weld metal grade 308L which deposited by SMA (Shielded Metal Arc) method with various ferrite content. Several tests such as tensile at room temperature, charpy impact V-notch and lateral expansion at cryogenic temperature -196℃ were conducted to observe mechanical behaviour. Electrochemical testings such as Cyclic Polarization method and Electrochemical Impedance Spectroscopy (EIS) were also performed. Controlling weld metal 308L with ferrite number (FN) 2 and manganese content about 1.53 % could achieve excellent toughness and hot cracking resistance as well as improved pitting corrosion resistance for cryogenic purpose.