This paper presents the findings of fatigue strength tests of 15CrNi6 steel following low-pressure carburizing and oil quenching, subjected to cycles of one-sided three-point bending. The fatigue fractures were compared with the results of fatigue strength studies of 16MnCr5 steel following low-pressure carburizing and nitrogen quenching. The fatigue tests for 16MnCr5 steel were conducted as part of a high-cycle resonance test, with a pendular bending load. The study also involved an analysis of the effects on non-metallic inclusions in the structure on the mechanism of fatigue destruction. The inclusions were found to initiate fatigue cracks. In both cases, a similar method of a fatigue fissure initiation was observed, independent of the study method or specimen material.
The copper droplets contained in the post-processing liquid slag are subjected to the treatment by the complex reagent. The complex reagent has been recently elaborated and patented in frame of the Grant No. PBS3/A5/45/2015. In particular, the complex reagent is dedicated to the post-processing slags coming from the Smelter and Refinery Plant, Głogów, as a product of the direct-to-blister technology performed in the flash furnace. The recently patented complex reagent effectively assists not only in agglomeration, and coagulation but also in the deposition of the copper droplets at the bottom of crucible / furnace as well. The treatment of the postprocessing slags by the complex reagent was performed in the BOLMET S.A. Company as in the industrial conditions which were similar to those usually applied in the KGHM – Polish Copper (Smelter and Refinery Plant, Głogów). The competition between buoyancy force and gravity is studied from the viewpoint of the required deposition of coagulated copper droplets. The applied complex reagent improves sufficiently the surface free energy of the copper droplets. In the result, the mechanical equilibrium between coagulated copper droplets and surrounding liquid slag is properly modified. Finally, sufficiently large copper droplets are subjected to a settlement on the crucible / furnace bottom according to the requirements.