The main objective of this work was to determine the optimal parameters of heat treatment of a welded joint on austenitic stainless-steel pipes grade X2CrNi18-9. The pipes have an outer diameter of 8 mm and are used in cooling chambers. The theoretical part describes the systematization of stainless steels, their mechanical properties, and areas of application. The behavior of various stainless steel during welding was described especially for austenitic stainless steels. The experimental part describes the production process of pipes, which are made of sheet metal 30 mm wide and 0.5 mm thick. The pipes are welded by plasma welding, calibrated and heat treated by annealing at 1050 ° C. The duration of annealing and the cooling rate depends on the passing speed of the pipes through the furnace, ie. on the speed of the pipe winding on the coil, which is currently used 0.85 m/min. The possibility of improving productivity by increasing the speed was investigated along with satisfactory properties of the welded joint. To determine the optimal speed, the microstructure was analyzed and the microhardness was measured in the base material, the weld metal, and the heat affected zone at the welded pipe joints. The bending properties of welded joints were also investigated. Based on the obtained results, the optimal value of the passing speed of the pipes through the furnace is 1.00 m / min. This heat treatment condition is achieves a homogeneous microstructure, low microhardness and excellent pipe flexibility, and productivity in the heat treatment phase increases by about 18%.