27th IFHTSE CONGRESS & EUROPEAN CONFERENCE ON HEAT TREATMENT 2022

Recently, it has been reported that CoCrFeNiMn high-entropy alloy (HEA) has excellent tensile strength and ductility at HEA at low temperatures. Through plasma nitriding at 673 K, an expanded fcc structure was formed on the surface of the HEA. Another study observed that dislocations were introduced on the surface of CoCrFeMn alloy powder through ball-milling. Simultaneously, strength...

Gas nitriding processes with cyclical rotation of ammonia and ammonia/air atmospheres are studied for surface strengthening of Cr-Ni corrosion resistant steels. One-, two-, and three-staged processes were experimentally investigated differing by gas atmospheres at the final stage of the processes. Gas-cyclic nitriding provides an intensification of saturation of alloyed steels with ...

A high-entropy alloy (HEA) is a multi-component alloy obtained by blending at least five metals with compositions of 5%~35%. Generally, HEAs are produced by arc melting and casting. The cast specimens undergo phase segregation and have heterogeneous microstructures. CoCrFeNi is the most investigated high-entropy alloy system. In this study, we used pure Co, Cr, Fe, Ni, and Zr pure powders as...

The development of plasma nitrocarburizing processes for steel treatment is important for establishing of an environmentally friendly heat treatment process. One of the strategies is to apply the main discharge power on a so-called active screen (AS). The AS surrounding the workload provides heat and reactive species to the workload. The treatment conditions are controlled by the discharge...

The influence of solution treatment duration on microstructural and mechanical properties of a cold-rolled Ti-30Nb-12Zr-5Ta-2Sn-1.25Fe (wt.%) (TNZTSF) alloy was investigated in this study. The TNZTSF alloy was produced by cold-crucible induction in levitation synthesis technique, in argon-controlled atmosphere. After synthesis the alloy was processed by cold-rolling deformation, with a total...

The nickel super alloy 625 can be used for mechanical applications on the solid solution state but has its applicability in aeronautic, aerospace, marine, chemical and petrochemical industries when improvement on mechanical resistance by age-hardening treatments are performed. In this study the grain growth, precipitation and phase transformation were evaluated in a commercial superalloy 625....

The paper compares the abrasion and erosion resistance of two high-alloy tool steels, EN X153CrMoV12 and Böhler K390 MICROCLEAN, coated with multilayer coatings TiN / TiCN and TiN / Ti-B-N. Multilayer coatings were applied to hardened and tempered samples by pulsed direct current (DC) plasma-assisted chemical-vapour deposition (PACVD) process in the Rübig PC 70/90 industrial vacuum oven. The...

A precise understanding of compound layer growth on nitrocarburized steels requires fundamental investigations on nitrocarburizing of iron-based binary and ternary alloys. Such studies were extensively carried out for the case of nitriding. To this end, this study is devoted to understanding the role of V on the structure and morphology of iron-carbonitrides developed during salt bath...

Prior severe surface plastic deformation (SSPD) treatments have proven beneficial to low-temperature nitriding to achieve a thicker nitride layer, improved hardness, and wear resistance. Although extensive work has been reported on SSPD followed by nitriding; however, cyclic treatment of SSPD and low-temperature nitriding on austenitic steels (ASS) is not reported. Also, the role of...

AISI H13 tool steel presents a good combination of mechanical strength and toughness, with this, they are used, as examples, in the manufacture of aluminum extrusion dies, hot forging dies and injection molds of non-ferrous materials and polymers. These tools, in practice, are subjected to tensile and compression stresses during the heating and cooling process, which lead to thermal fatigue...

Selective laser melting technology (Powder Bed Fusion - " material melting in a pre-formed layer" according to ASTM classification) is one of the most promising additive manufacturing technologies because it has a number of fundamental advantages such as zero-waste, versatility, the ability to manufacture complex-shape parts with high accuracy that are not inferior to and sometimes exceeding...

For the determination of the hardness penetration depth in thermally hardened steel parts we present a non-destructive, contactless methodology based on laser-ultrasound and supervised machine learning. Ultrasound pulses are excited at the surface by a pulsed laser source. These propagate into the sample and are preferentially backscattered at the interface between hardened layer and core due...