Peculiarities of the Formation of a Hardened Layer During Laser Borinizing of Piston Rings

Abstract

Insufficient wear resistance of piston ring materials often limits the growth of machine productivity and service life. The use of traditional drilling methods associated with the diffusion of boron into the solid phase will lead to the formation of a working layer with high fragility. Therefore, the problem of increasing the wear resistance of piston rings without embrittlement is relevant. The use of laser heating during drilling provides the formation of a new layer with special properties. However, optimal properties can only be achieved after the relationship between the process parameters and the depth of the bored layer has been established. The influence of laser heating parameters on the composition and depth of the drilling layer is established in the work. The results of research can be extended to other parts that are subject to intensive wear.

Increasing the Corrosion Resistance of Heat-Resistant Alloys for Parts of Power Equipment

“…The Inconel 718 heat-resistant austenitic alloy of the Fe-Cr-Ni system and the 12X18H10T and SLS 316L corrosion-resistant steels were selected as the materials for the study. Inconel 718 alloy is a heat-resistant nickel alloy of the Fe-Cr-Ni system and is used in details of power equipment for the manufacture of details of power equipment combustion chamber jackets, parts of turbopump assemblies and other critical duty products [8][9][10][11][12]. The alloy is used in the temperature range from -252.8 to +704.4 °С, and is stable in chemically active gaseous environments at the temperature of up to +980 °С [7].…”

“…Tests and studies were performed on the equipment of a machine-building enterprise. The ICC tests were carried out using the "АМ" method in accordance with GOST 6032-89 [7][8][9][10]: the welded samples were boiled for 24 h in a sulfuric acid solution with the addition of copper sulfate and copper chips, then the samples were bent by 90 degrees. The bending point was controlled by visual inspection and metallographic method using МБС and Neophot-2 microscopes with magnification up to 200 times 5•10 mm samples for the manufacture of metallographic specimens were cut from the bending sections.…”

“…In these pairs, atoms of a more active metal (usually Fe) play the role of an anode, and atoms of a less active metal play the role of a cathode. At the cathode, there is a reduction process of O 2 molecules in neutral and alkaline mediums, or of H +ions in an acidic medium [5,6,8,9].…”

“…Corrosion resistance of steels is achieved by alloying steels with chromium or chromium and nickel [4]. Corrosionresistant steels can be classified by structural class as ferritic, pearlitic, martensitic and austeniticdepending on the structure after heating the steels in the austenite field and cooling in air [9][10][11][12][13].…”