scholarly journals Formation of Multiple Phase Microstructure and Wear Investigation on Treated AISI 904L SS by Low Temperature Ion Nitriding Process

2020 ◽  
Vol 184 ◽  
pp. 01001
Author(s):  
Ram. Subbiah ◽  
N. Sateesh ◽  
S.K Singh ◽  
S. Ravi Sekhar ◽  
B. Tanya ◽  
...  

In industries, components have to operate under extreme prerequisites such as high load, speed, temperature and at a chemical environment. The materials are selected by commercial availability, cost and by considering by their properties like strength, hardness etc. AISI 904L is a high alloy stainless steel with low carbon content material having poor hardness on the surface and negative wear properties. Many of the engineering failures are due to fatigue, corrosion and poor wear resistance which are initiated in its surface. This causes cracks in the surface which reduces the life of the material. Also the surfaces of the materials are caused by severe thermal, chemical and shock loads. Chosen for this work, AISI 904L materials were subjected to plasma or ion - nitriding process and were treated to 3 different timing parameters like 24 hrs, 48 hrs and 72 hrs respectively, maintaining constant temperature of 650oC. Among the availability of other nitriding process like gas and liquid nitriding, plasma nitriding gives good dimensional stability, uniform treatment, less distortion, uniform case depth irrespective towards size and shape of the specimen. For analyzing the wear properties, a pin on disc machine is utilized making the pin to get weared on disc against a load of 100N at a speed of 1000 rpm. Finally the metallographic studies were done by Scanning Electron Microscopic analysis.

2015 ◽  
Vol 830-831 ◽  
pp. 675-678
Author(s):  
M. Agilan ◽  
T. Venkateswran ◽  
D. Sivakumar ◽  
Bhanu Pant

Low carbon stainless maraging steel (0.03%C-12%Cr-10Ni-0.6Mo-0.2Ti) is being used widely for various components of the aerospace engines. To improve the wear resistance of the steel various surface hardening processes are being utilized to improve the surface hardness above 900HV. In this present research, plasma nitriding was carried out at two different temperatures of 450 °C and 475 °C for the holding duration of 10 hrs. Temperature of the nitrding process was ensured below the ageing temperature (500 °C) of the steel to avoid lowering of mechanical properties. Effect of plasma nitriding parameters on the surface hardness, case depth, microstructure and phases present in the nitrided layer were investigated in detail using microhardness analysis across the nitrided layer, X-ray diffraction (XRD), optical microscopy and scanning electron microscopy (SEM). It was observed that increase in nitriding temperature increased the surface hardness and case depth. In addition, the presence of Fe3N and Fe4N phases in the nitrided layer were observed using X-ray diffraction technique.


2021 ◽  
Vol 309 ◽  
pp. 01181
Author(s):  
K. Ramya Sree ◽  
D. Raguraman ◽  
J. Saranya ◽  
Animesh Bain ◽  
V. Srinivas Viswanth ◽  
...  

In industries, components must operate under extreme conditions such as high load, speed, temperature and chemical environment. Materials are selected according to commercial availability, cost and their properties such as strength, hardness, etc. AISI 904L is a high-alloy stainless steel with low carbon content, poor surface hardness and wear characteristics. Many engineering failures are caused by fatigue, corrosion, and poor wear resistance, begins at the surface level. This causes cracks in the surface, reducing the material’s life. The surfaces of the materials were subjected to severe thermal, chemical, and shock loads. The selected AISI 904L materials for this work were subjected to gas nitriding process and processed with 3 different time parameters such as 12 hours, 18 hours and 24 hours respectively and named as GN1, GN2 and GN3. The treatments were done at a constant temperature of 650°C. Gas nitriding, in comparison to other nitriding processes such as plasma and liquid nitriding, provides good dimensional stability, reduced deformation, and uniform case depth regardless of the size and shape of the specimen. To analyze the wear properties, a pin on a disc machine is used. Finally, metallographic studies were performed by scanning electron microscopy.


Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 861
Author(s):  
Minako Kubo ◽  
Minako Tachiki ◽  
Terumasa Mitogawa ◽  
Kota Saito ◽  
Ryota Saito ◽  
...  

Solution-cast coating films of perchlorate-doped oligo(3-methoxythiophene) exhibited a gold-like luster similar to that of metallic gold despite the involvement of no metals. However, the development mechanism of the luster remains ambiguous. To understand the mechanism, we performed scanning electron microscopic analysis, variable-angle spectral reflectance measurements, and ellipsometry measurements on ClO4−-doped oligo(3-methoxythiophene) cast film with a gold-like luster. The results revealed that the lustrous color of the film was not induced by the submicron-sized regular structures (structural color), nor by the high-density free electrons (reflective response based on Drude model), but by the large optical constants (refractive index and extinction coefficient) of the film, as speculated previously.


1986 ◽  
Vol 64 (11) ◽  
pp. 2467-2479 ◽  
Author(s):  
William G. Young ◽  
Therese M. Marty

A group of wild moose from Manitoba, Canada, were documented as having excessive tooth wear. Replicas of one incisor tooth were collected from 16 individuals and from 19 controls for comparison by volumetric and scanning electron microscopic analysis. All animals were aged from tooth cementum lines. Tooth replicas were cast from silicone rubber impressions in epoxy resin and sputter coated with gold. Tooth wear with age was compared statistically by measuring crown height, percent tooth loss, interfacet distance, and facet area on the incisors. The unique pattern of wear on the anterior teeth of affected moose was described. In affected animals, crown heights were significantly reduced and percent tooth loss was excessive. Microwear analysis found that an abrasive agent, acting predominantly in a lingual to labial direction, had been responsible for loss of enamel and dentine incisally and interproximally, and on the facial and lingual surfaces to a lesser extent. Interdental facets became involved by vertical abrasion. Control teeth showed fewer but coarser scratches and only approached the pattern of wear found in affected moose in a few individuals in old age. The loss of tooth structure would lead to diminished cropping efficiency and damage to the periodontium.


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