Theoretical research of ultrasonic wave propagation in austenitic steel welds was performed and integral equations were applied to the problem of planar ultrasonic wave scattering in anisotropic polycrystal medium. The problem was solved using the Born approximation and analytical calculations were carried out for an austenitic metal weld and the weld thermal influence zone. The calculated values for scattering coefficients were used for calculating the attenuation of ultrasonic signals passing through austenitic welds. Energetic and geometric factors of ultrasonic wave intensity attenuation in austenitic welds were considered and formulas to calculate the deviation angle of the acoustic beam from wave normal and acoustic beam deformation coefficients in a weld were obtained as well. With the example of a single V-butt weld in 12H18N10T steel (analogous 321 H steel) a calculation of the value of ultrasonic signal attenuation and a prediction of the ultrasonic beam outcoming point location were carried out in the present work.