A Programmable System for Treatment of Alloy Steels at Cryogenic Temperatures

2011 ◽  
Vol 264-265 ◽  
pp. 1240-1245 ◽  
Author(s):  
F. Farhani ◽  
Keyvan Seyedi Niaki

Treatment of alloy steels at cryogenic temperatures increases their wear resistance, which is an important consideration in industrial applications. The treatment of metal samples is performed in a dedicated cryogenic processor, with provisions for precise time/temperature control of the samples on the basis of pre-defined temperature protocols. There is little information on the design and construction of cryogenic processors in the open literature. In this paper, development of a simple and inexpensive programmable processor for treatment of metals at cryogenic temperatures has been presented. Considerations for the selection of suitable cooling method and reduction of liquid nitrogen consumption have been discussed. To demonstrate the usefulness of this processor, a metal sample has been cryotreated. Results of the treatment show a more uniform microstructure and less retained austenite in the treated metal sample, which is due to the transformation of most of austenite into the harder martensite phase. Overall results show that the design methodology presented in this paper can be adopted by other researchers for constructing similar processors for studying the effect of cryogenic temperatures on enhancement of wear resistance and other mechanical properties in metals.

1994 ◽  
Vol 3 (11-12) ◽  
pp. 1381-1384 ◽  
Author(s):  
G.D. Gamulya ◽  
Ye.L. Ostrovskaya ◽  
I.L. Ostapenko ◽  
G.N. Presnyakova ◽  
V.E. Strel'nitskij

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 712 ◽  
Author(s):  
Peiyou Li ◽  
Xindi Ma ◽  
Duo Wang ◽  
Hui Zhang

The microstructural and mechanical properties of β-type Ti85-xNb10+xSn5 (x = 0, 3, 6, 10 at.%) alloys with low elastic modulus were investigated. The experimental results show that the Ti85Nb10Sn5 and Ti75Nb20Sn5 alloys are composed of simple α and β phases, respectively; the Ti82Nb13Sn5 and Ti79Nb16Sn5 alloys are composed of β and α″ phases. The content of martensite phase decreases with the increase of Nb content. The Ti82Nb13Sn5 and Ti79Nb16Sn5 alloys show an inverse martensitic phase transition during heating. The Ti85Nb10Sn5 and Ti82Nb13Sn5 alloys with the small residual strain exhibit the good superelastic properties in 10-time cyclic loading. The reduced elastic modulus (Er) of the Ti75Nb20Sn5 alloy (61 GPa) measured by using the nanoindentation technique is 2–6 times of that of human bone (10–30 GPa), and is smaller than that of commercial Ti-6Al-4V biomedical alloy (120 GPa). The Ti75Nb20Sn5 alloy can be considered as a novel biomedical alloy. The wear resistance (H/Er) and anti-wear capability (H3/Er2) values of the four alloys are higher than those of the CP–Ti alloy (0.0238), which indicates that the present alloys have good wear resistance and anti-wear capability.


JOM ◽  
2021 ◽  
Author(s):  
Joalet Dalene Steenkamp ◽  
Kondwani Wesley Banda ◽  
Pieter Johannes Andries Bezuidenhout ◽  
Glen Michael Denton

AbstractThe Pyrometallurgy Division at Mintek is known internationally for the development of applications of direct current (DC) arc furnace technology in smelting applications, more specifically in the smelting of primary resources, i.e., chromite, ilmenite, titanomagnetite, nickel laterite and ores containing precious group metals, and secondary resources, i.e., furnace slag or dust. From a furnace containment perspective, either an insulating or a conductive design philosophy can be applied, irrespective of the raw material being processed. In the initial stages of a project, desktop studies are typically conducted which include the selection of a furnace containment design philosophy, specific to the application. To lower the risk associated with incorrect selection of a design philosophy and/or furnace containment system components, it is prudent to conduct tests on laboratory and pilot scale and to transfer the knowledge gained to industrial applications. The paper presents examples of the laboratory and pilot techniques utilized.


Author(s):  
D. M. Berdiev ◽  
M. A. Uмаrоvа ◽  
A. A. Yusupov

The relationships between the parameters of the structure of heat‑treated steels and their abrasive wear resistance are established. At all temperatures of the final tempering of hardened steel, there is a direct relationship between its structure parameters (the number of elements in a solid solution, the density of dislocations, the size of cementite particles and the intercementite distance) and wear resistance when sliding friction against loose abrasive particles. A computer program has been developed to select the chemical composition of the steel grade and methods of thermal hardening in order to ensure the required wear resistance.


2014 ◽  
Vol 966-967 ◽  
pp. 386-396 ◽  
Author(s):  
Yuan Ching Lin ◽  
Jia Bin Bai ◽  
Jiun Nan Chen

The austenitic stainless steel (SS) of AISI 304L is widely used in industrial applications because of its superior anti-corrosion resistance. However, the material suffers from a lower hardness, thus reducing wear resistance. In this study, AISI 304L was clad with tungsten boride (WB) ceramic powder using the gas tungsten arc welding (GTAW) process to increase surface hardness and improve wear resistance. The microstructure of the cladding layer was investigated using an X-ray diffractometer (XRD), an electron probe microanalyzer (EPMA), and a scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS). The hardness distribution of the cladding layer was measured using a micro-Vickers hardness tester. Wear tests were conducted with a pin-on-disc tribometer at the ambient condition, while simultaneously monitoring friction coefficient variation. Surface frictional temperature was recorded with K-type thermocouples during wear tests. The worn morphology of the tested specimens was observed by SEM to identify wear characteristics. The results show that WB cladding successfully increased the hardness and the wear resistance of AISI 304L. Keywords: GTAW, WB, wear resistance, microstructure


2018 ◽  
Vol 36 (5) ◽  
pp. 435-447 ◽  
Author(s):  
Roshan Kuruvila ◽  
S. Thirumalai Kumaran ◽  
M. Adam Khan ◽  
M. Uthayakumar

AbstractThe efficiency of industry depends upon the working conditions of the equipment and components used in the industrial process. The biggest problems faced by the industries are the problems of erosion and corrosion. The harmful effects of corrosion will lead to material loss, which results from the degradation of the equipment. The degradation of the equipment will cause the breakdown of the plant; moreover, it is a threat to the safety of people, and also from the point of conservation, it can cause the exploitation of available resources. The cost of replacing equipment increases the expense, and it can also result in the temporary shutdown of the plant. The protection of surfaces from the adverse effects of corrosion and erosion-corrosion is a matter of great concern in most industrial applications. Advancements in technology provides a wide range of techniques to overcome adverse conditions. The selection of appropriate technology must be from the viewpoint of their interaction with the environment. This review paper addresses the adverse effects of erosion-corrosion in the present scenario.


2018 ◽  
Vol 70 (8) ◽  
pp. 1408-1413 ◽  
Author(s):  
Hongjin Zhao ◽  
Lei Cao ◽  
Yong Wan ◽  
Shuyan Yang ◽  
Jianguo Gao ◽  
...  

Purpose The purpose of this paper is to increase wear resistance of aluminum. Design/methodology/approach The authors have studied the ways to improve the tribological performance of aluminum by assembling stearic acid on aluminum coated by sol-gel-derived TiO2 film. The samples were characterized by infrared spectroscopy, contact angle measurements and a macro friction and wear tester. Findings Enhanced wear resistance was clearly obtained after functionalization of TiO2 film on aluminum by stearic acid. Originality/value The relevant results might be helpful for guiding the surface modification of aluminum devices in industrial applications.


2021 ◽  
pp. 51-54
Author(s):  
D.V. Glazunov ◽  
V.N. Krotov ◽  
E.Yu. Cherkesov

The main ways to strengthen and increase the resourse of wheelset bandage as result of which it is determined that the most economical and quick-to-implement method is the use of tribotechnical materials are considered. The main disadvantage in using of tribotechnical materials is the limited temperature range of rolling stock operation is determined. Qualitative selection of anti-wear and heat-resistant additives, as well as binder is perfomed based on the physical properties required for tribotechnical materials and the range of component content in the lubricant is determined. The wear resistance of wheelset bands is increased by 28 % as result of performance tests.


2021 ◽  
Vol 35 (04) ◽  
pp. 2150057
Author(s):  
Qunfeng Zeng ◽  
Khashayar Khanlari ◽  
Naiming Lin

Equiatomic and near equiatomic NiTi alloys, showing good mechanical and thermal shape memory properties, are widely exploited in different industrial applications. In addition, NiTi alloys have promising anti-cavitation and corrosion-resistance properties. These advantages have provided opportunities to exploit NiTi alloys as the coatings for protecting materials used in the industrial applications. This study is a preliminary investigation aiming to evaluate the feasibility to form NiTi alloy coatings on SS304 steel by tungsten inert argon arc welding (TIG) technology. The microstructure analysis shows that the crystalline phases in NiTi coatings on SS 304 steel are TiNi-B2, TiNi-B19’ and Ni3Ti. The potential of the NiTi coatings to enhance the corrosion resistance and cavitation resistance behaviors of steel exposed to seawater is studied. NiTi coatings, with two different thicknesses of about 1.2 and 2 mm, having homogenous microstructures were successfully deposited on SS304 steel using TIG technology. Results of tests, done in aqueous solutions simulating seawater, showed that the formation of the oxide films on the surface of NiTi coatings increased the corrosion resistance and wear resistance and decreased the damage caused by the cavitation. Moreover, it was understood that the NiTi coatings with 2 mm in thickness show the superior performances than those with 1.2 mm in thickness. The tribological mechanisms responsible for the unique properties of NiTi alloy coatings were investigated. The wear-resistance behaviors of NiTi alloy coatings are greatly influenced by the friction conditions. Increasing load decreased CoF and the wear rate of the coatings were almost constant, which was attributed to the pseudoelasticity of NiTi alloy. The attractive properties of NiTi alloys that makes it most influential materials for industrial applications have also been discussed.


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