INSPECTION BY NDT-DT TESTING TO ANALYSE AND CONTROL FRICTION ROTATING WELDING OF AISI 304L AND AISI 316L STAINLESS STEEL GRADE

The quality of the weld primarily depends on the parameters used during the welding process, including rotational speed, friction time and pressure, and forging time and pressure. Initially, welding operations are carried out on austenitic stainless steel bars, specifically from the AISI 304L and AISI 316L families, under a constant rotational speed. The first objective is to analyse the steel AISI 304L using the effect of two simultaneous parameters, namely two different forging times and two different forging pressures. The second objective is to evaluate the effect of five different friction phase times on AISI 316L, while keeping the other parameters constant, including friction pressure and forging pressure. Subsequently, a quality control is performed on all welded joints using non-destructive testing (NDT) techniques such as dye penetration testing, X-rays, and ultrasonics, in order to assess the impact of the aforementioned welding parameters on the quality of the joints. The results obtained indicate the presence of defects in some of the welded joints, estimated at 25 % in terms of joints, predominantly associated with low forging times or pressures.