Improvement of Wear and Corrosion Resistance of Austenitic Stainless Steel by Combined Treatment Using Electron Beam Cladding and Subsequent Gas Nitrocarburizing

Abstract

The high passivation capacity of austenitic stainless steels results in excellent corrosion resistance in a wide variety of corrosion media. However, the tribological properties of these steels are insufficient due to their low hardness and high susceptibility to adhesive wear. To improve the wear behavior of austenitic steels while maintaining corrosion resistance, thermochemical processes such as nitriding or nitrocarburizing can be used. Such processes can be carried out as single procedures or in combination with coating techniques. Herein, the results of a new combination treatment consisting of the electron beam cladding (EBC) of a Co‐based alloy with subsequent gas nitrocarburizing (GNC) are presented. The effects of the beam deflection technique on the microstructure and phase formation of the cladded wear protection layer, the resulting hardness as well as the dilution ratio and the bonding of this layer to the base material are demonstrated. The subsequent gas nitrocaburizing leads to the formation of an ≈10 μm‐thick surface layer enriched with nitrogen and carbon. The significant improvement in wear resistance compared with the untreated base material is demonstrated by abrasive and adhesive‐abrasive wear tests. Corrosion resistance is investigated by recording current density—potential curves and long‐term tests in corrosive media.

Laser‐Directed Energy Deposition Additive Manufacturing of Nickel–Titanium Coatings: Deposition Morphology, Microstructures, and Mechanical Properties

“…A typical cross‐section of the LDED‐processed deposition track was schematically shown in Figure , the height h , penetration depth b , deposition track width w , and wetting angle θ were indicated, and all of them can be measured by Toupview software. The dilution ratio D of LDED‐processed deposition tracks can be calculated as follows [ 30 ] where A d is the molten area below the substrate and A p is the deposited area above the substrate. The phase constituents of powder and LDED‐processed samples were identified by the Thermo Scientific TM ARLTM TM X’TRA XRD with Cu Kα radiation ( λ = 0.154 18 nm), using a continuous scan mode.…”

“…A typical cross-section of the LDED-processed deposition track was schematically shown in Figure 3, the height h, penetration depth b, deposition track width w, and wetting angle θ were indicated, and all of them can be measured by Toupview software. The dilution ratio D of LDED-processed deposition tracks can be calculated as follows [30]…”

Novel Corrosion‐Resistant Tool Steels with Superior Wear Properties

“…[11] Nevertheless, a lot of research has been already performed on the corrosion behavior of steels in different corrosive environments and the general effects of alloying elements on the corrosion mechanisms are well examined. [12][13][14][15][16][17] Chemically resistant steels and cast irons can withstand a chemical attack during wet corrosion by forming a thin chromium oxide-based layer on the surface and, thus, significantly impeding the corrosion progress. By increasing the Cr content, a thin porous crystalline film changes into a dense amorphous passive layer.…”

Evaluation of Passivation Process for Stainless Steel Hypotubes Used in Coronary Angioplasty Technique

“…One of the most generally accepted is the formation of a stable OH-(oxy-hydroxide hydrate) film in the area of a few millivolts around the redox potential, E corr . More recent articles have brought new information about the passivation process of austenitic steels [31][32][33][34][35], including the role of molybdenum in their passivation [36].…”