Dry Sliding Wear Behavior of AISI310 Stainless Steel with Low Temperature Salt Bath Nitriding and Gas Nitriding Processes

AISI 310 is an austenitic stainless steel that accomplished in high thermal applications like turbines, boiler parts etc. In this study AISI310 was treated with salt bath nit- -riding for 60min, 120min and 150min and gas nitriding for 6hrs, 12hrs and 18hrs at the temperature of 5700 c respectively. Comparison study of nitrided specimens were performed under various metallographic tests like scanning electron microscope, X-ray Diffraction, pin on disc apparatus. Experimental results shown that when salt bath nitrided sample at 150min showed a white layer called “S-phase” layer which was detected. In gas nitriding also “S-phase” layer, an expanded austenite was observed, after 18 hrs, CrN phase was discovered after the decomposition of s-phase layer gas nitrided sample of 18hrs which showed the best corrosion resistance .Salt bath specimen 150 min showed minimum wear loss and gas nitrided sample of 18hrs showed more hardness, minimum wear and improved corrosion resistance compared to untreated sample.

Comparative Study on the Effect of Nitriding and Microwave Coating on Microstructure, Hardness and Wear of AISI H13 Tool Steel

Heat treatment and surface processing are critical aspects of design and manufacture of components in a wide range of industrial sectors. Engineering materials, such as steel, are heat treated under controlled heating and cooling to alter their chemical, physical and mechanical properties to meet desired engineering applications. Gears engaged rotating at several thousand RPM. Inner Barrels of Injection Moulding machines, which is subjected to wear when thermoplastics, glass fibres are chosen to be injection moulded, Guide pillar Guide bush which slide over each other needs to be hardened from outside to improve hardness and wear resistance, but ductile from inside to bear fluctuating load, for this types of operation Case Hardening is required, to give desired property. In this detailed and systematic investigation, we have selected AISI H13 tool steel as for our research work specimen and we have made an effort to find out the mechanical properties (EDX, Hardness HV, Pin on Disc wear test) and micro structural properties (SEM, XRD) by comparing the two process one is traditional Case hardening heat treatment process i.e. Gas Nitriding and a new process i.e. Coating of Ni-based alloy powder on H13 Tool steel by Microwave Hybrid Heating (MHH) method in household microwave oven at 900W and 2.45 GHz and further find the best process. Investigation shows that coated Sample has good Wear resistance as compared to unmodified H13 Tool Steel sample and nitrided sample, Vicker’s micro-hardness of nitride sample is found to be 829.5HV, and for coated sample is 788HV, Coated sample has good Microstructure as compared to nitrided sample and is free from porous cracks.

Hardness of Duplex Treated Stainless Steel

This chapter describes how the aim of duplex surface engineering includes chronological application of two surface modification technologies for the production of a surface, with collective properties. Duplex treatment of nitriding and carbonitriding of austenitic stainless steel is of high technical importance owing to its capability to increase hardness, corrosion and wear resistance of treated surface. Duplex treatment has been utilized to enhance the surface mechanical properties of austenitic stainless steel (AISI 304). The microstructure of nitrided surface indicates the development of nitride phases, Fe4N, Fe2N, CrN, Cr2N and γN whereas, duplex treated films shows the formation of FeC, Fe3C, Fe7C3, Cr3C2, Cr7C3, along with nitride phases like Fe3N. Both nitrided and duplex treated samples show the formation of cauliflower like grains. Surface micro hardness of treated substrates has been dependent on the variation of crystallite size and increased by 1.26 times the hardness of nitrided sample and 4.60 times the hardness of the untreated substrates.

Comparison of AISI 316L Plasma Nitriding Behavior in Low and Medium Temperature

Plasma nitriding is a widely used technique to improve the mechanical properties and tribological properties of AISI 316L steel because it has many advantages over other surface treatment techniques. One of this advantage is plasma nitriding allows nitrogen introduce to steel at low temperature (below 500°C).In this study, nitriding of an AISI 316L was performed in high density plasma nitriding system using 70%N2:30%H2 gas mixture at 400°C and 480°C for 2, 4, and 8 hours. Optical Emission Spectroscopy (OES) with optical probe was used for plasma diagnosis. The properties of nitrided sample were investigated through microhardness measurement. The results show that N2 ions and radicals are species predominantly formed in plasma.

PLASMA NITRIDING FOR IMPROVING WEAR RESISTANCE OF CABLE BOLT

In order to improve the wear resistance of the cable bolt and increase its life-time during operation, plasma nitriding was employed to obtain a protective nitriding layer on its surface. The microstructure, phase constitution, microhardness and wear resistance of the nitriding layer were investigated. It was shown that continuous and dense nitriding layers were formed on the surface of the samples. The microhardness of the nitrided sample was enhanced by the formation of nitriding layer, which mainly consisted of Fe 4 N and Fe 3 N . The mass losses of the nitrided samples were much smaller and the wear rates were almost hundred times lesser than that of the substrate. Plasma nitriding treatment can effectively enhance the wear resistance of cable bolt.

Effect of Nitridation on Indium-Composition of InGaN Films

The Present Study Aims to Understand the Relation between the Nitridation and Indium-Composition of Ingan Grown on Sapphire Substrate Using the Metalorganic Vapor Phase Epitaxy through X-Ray Diffraction Reciprocal Space Mapping Measurements. In-Composition of InGaN on Nitrided Sapphire Substrate Increased to 13% which Is Higher than the Sample without Nitridation with 7%. Also, Flat Surface Was Observed in the Nitrided Sample. Two Times Larger in-Plane Strain Was Induced at the Nitired Sample. Ingan Grown on Low-Temperature Gan Buffer, however, Did Not Show Clear Effect of Nitridation. The Two Investigated Samples Showed Similar Indium Composition, Surface Flatness, and in-Plane Strain with and without Nitridation. Differences of Indium Incorporation and Relaxation of in-Plane Strain Were Attributed to the Effect of AIN Formed by Nitridation Process.

Plasma Nitriding of 20CrMo Steel with Nanostructured Surface Layer

A nanostructured surface layer was produced on an 20CrMo steel plate by means of ultrasonic shot peening (USSP) treatment. Plasma nitriding of the treated and un-treated sample were investigated by using structure analysis (X-ray diffraction, optical microscopy, and transmission electron microscopy ) as well as hardness measurements. It was found that a nanostructured surface layer sample developed a compound layer twice as thick as that in a coarse-grained sample under the same plasma nitriding conditions (530 oC for 6 h). In addition, the USSP nitrided sample exhibited higher hardness and thicker hardened surface layer in comparison with coarse-grained nitrided sample.

Research on Corrosion Resistance of Titanizing and Nitriding on Carbon Steel in H2SO4 Solution

Q195 steel was treated with titanizing followed plasma nitriding by glow plasma alloying technology using single pulse power supply. The corrosion resistances of titanizing sample and titanizing + ion nitrided sample were studied. The results show that the alloying layer is 200 μm in depth and organization is α-Fe solid solution containing Ti by plasma titanizing technology using single pulse power supply. An obvious reactive diffusion dividing line formed between alloying layer and the substrate. It shows that diffusion phenomenon happened in process of titanizing. The morphology of Ti alloy layer was columnar crystals. The content of Ti on the surface is up to 5 wt%. And the Ti content of alloying layer is in a decreasing from the surface to the inner on a gradient distribution. The phase structure of titanizing layer is composed of Fe2Ti, Fe-Ti and TiC phases. The phase structure of titanizing + ion nitrided sample was obviously TiN phase and a few Fe-Ti phase. The surface hardness of untreated carbon steel is 110 HV and that of the alloying layer of titanizing is 310HV. The surface hardness of titanizing + ion nitrided sample is 1800HV. The corrosion resistance of titanizing sample is increased 12.15 times compared with the untreated sample and 1.42 times compared with 18-8 stainless steel in H2SO4solution; The corrosion resistance of titanizing + ion nitrided sample is increased 7.444 times compared with the untreated sample and as well as 18-8 stainless steel in H2SO4solution.

Europium nitride synthesized by direct nitridation with ammonia

Europium nitride (EuN), which is potentially used as an activator for nitride luminescent materials, was prepared by direct nitridation at 600 °C in a NH3 atmosphere. X-ray powder diffraction and composition analysis of the nitrided sample were carefully conducted under an oxygen-free environment. The nitrided sample was found to be mononitride with NaCl structure. An appreciable amount of oxygen (∼0.06 a.u.) was detected, but no secondary oxide phase was found. The results suggest oxygen dissolution into the lattice of EuN.