On the fatigue behaviour of electron beam and gas tungsten arc weldments of 409M grade ferritic stainless steel

Fatigue life and fatigue crack growth behaviour of the electron beam welded AISI 409M ferritic stainless steel joints in comparison with the gas tungsten arc welded joint and the base metal was studied. It is found that the joint fabricated by the electron beam welding process exhibited superior fatigue performance than that of the gas tungsten arc welded joint. Formation of a dual phase lath ferrite with fine martensitic microstructure, superior tensile properties and favourable residual stress field are the main reasons for the enhanced fatigue life and fatigue crack resistance of the electron beam welded joint.

► Fatigue behaviour of EBW and GTAW joints of ferritic stainless steel is reported.
► Effect of the microstructure, tensile properties and residual stresses are discussed.
► EBW joint showed superior fatigue performance compared to GTAW joint.
► Fine dual phase microstructure acted beneficially in retarding the crack growth.