THE REDISTRIBUTION OF SUBSTITUTIONAL AND INTERSTITIONAL ELEMENTS IN STEEL WELDMENTS (CSN-412013+0.0755N) (CSN-417241)/

The investigation of iron, chromium, nickel, carbon, and nitrogen redi stribution has been carried out in steel weldments (nitridized carbon steel)/(stainless steel) at 500 up to 1100 degrees C. It has been foun d that all elements, substitutional and interstitional, reveal measura ble redistribution after the applied diffusion anneals. The redistribu tion of substitutional elements has the character of interdiffusion an d carbon and nitrogen diffuse uphill from the nitridized carbon steel into the stainless steel. Metallographic observations and the shape of measured penetration curves confirmed the occurrence of nitridic zone s in CSN 417241 steel. The evaluated diffusion coefficients satisfy Ar rhenius relations whose characteristics depend on the structure of the weld joints. The limit concentrations C and N at the weld interface h ave enabled to calculate the thermodynamic interaction parameters epsi lon(C)(Cr), epsilon(N)(Cr), and epsilon(N)(C), for the given steel wel dments.