Nitrocarburising of Low Alloyed Case Hardening Steels Applying Three Different Temperatures

2012 ◽  
Vol 729 ◽  
pp. 13-18
Author(s):  
Andrea Szilágyi Biró ◽  
Miklós Tisza

Nitriding is one of the most important processes among surface technologies. The purpose of this process is to produce a wear resistant layer on the surface of components, to meet the complex requirements. Ferritic nitrocarburising was carried out at three different temperatures (520, 570 and 620°C) and with five different process times, to study the effects on process parameters . The experiments proved that in case of ferritic nitrocarburising, it is possible to produce larger diffusion zone during the same time. If the temperature is higher than the iron-nitrogen eutectoid temperature, the diffusion is deeper, but we should consider the softening of the core.

Alloy Digest ◽  
2021 ◽  
Vol 70 (3) ◽  

Abstract Lucefin C20 is a low-carbon, non-alloy steel that is used in the normalized, cold finished, or quenched and tempered condition. It may also be used in the carburized or carbonitrided, and subsequently quench hardened and tempered, condition for parts requiring a hard wear-resistant surface, but with little need for increased mechanical properties in the core. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: CS-209. Producer or source: Lucefin S.p.A..


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Liangbin Dou ◽  
Guanli Shu ◽  
Hui Gao ◽  
Jinqing Bao ◽  
Rui Wang

The investigation of changes in physical properties, mechanical properties, and microscopic pore structure characteristics of tight sandstone after high-temperature heat treatment provides a theoretical basis for plugging removal and stimulation techniques, such as high energy gas fracturing and explosive fracturing. In this study, core samples, taken from tight sandstone reservoirs of the Yanchang Formation in the Ordos Basin, were first heated to different temperatures (25-800°C) and then cooled separately by two distinct cooling methods—synthetic formation water cooling and natural cooling. The variations of wave velocity, permeability, tensile strength, uniaxial compressive strength, and microscopic pore structure of the core samples were analyzed. Experimental results demonstrate that, with the rise of heat treatment temperature, the wave velocity and tensile strength of tight sandstone decrease nonlinearly, yet its permeability increases nonlinearly. The tight sandstone’s peak strength and elastic modulus exhibit a trend of the first climbing and then declining sharply with increasing temperature. After being treated by heat at different temperatures, the number of small pores varies little, but the number of large pores increases obviously. Compared to natural cooling, the values of physical and mechanical properties of core samples treated by synthetic formation water cooling are apparently smaller, whereas the size and number of pores are greater. It can be explained that water cooling brings about a dramatic reduction of tight sandstone’s surface temperature, generating additional thermal stress and intensifying internal damage to the core. For different cooling methods, the higher the core temperature before cooling, the greater the thermal stress and the degree of damage caused during the cooling process. By taking into consideration of changes in physical properties, mechanical properties, and microscopic pore structure characteristics, the threshold temperature of tight sandstone is estimated in the range of 400-600°C.


Author(s):  
Shashikanth Ch ◽  
G Venkateswarlu ◽  
Davidson M J

The extrusion of copper-based aluminium alloys is difficult in the cold state. Extruding these alloys between the solidus and liquidus temperatures offer preferred properties on these alloys. In the present work, AA2017, a copper-based aluminium alloy has been extruded in the semi-solid state. The mechanical and metallurgical properties of the alloy vary at different temperatures between the solidus and liquidus temperatures. The aim of the present work is to optimize the process parameters, namely, temperature of billet, strain rate, approach angle and percentage reduction in area on the semi-solid extrusion of AA2017 alloy. Experiments were designed according to Taguchi experimental design and L9 orthogonal array was used to conduct the experiments. Analysis of variance (ANOVA) method was used to find the significance of every process parameter on the thixo-extrusion process responses. The results indicate that percentage reduction area is the most important factor influencing the mechanical properties of thixo-extrusion specimen followed by temperature and strain rate.


2020 ◽  
Vol 381 ◽  
pp. 125141 ◽  
Author(s):  
Jiankang Huang ◽  
Shien Liu ◽  
Shurong Yu ◽  
Xiaoquan Yu ◽  
Huizi Chen ◽  
...  

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dipti Rawat ◽  
P. B. Barman ◽  
Ragini Raj Singh

Abstract The selected and controlled preparation of core@shell nanostructures, which unite the multiple functions of ferromagnetic Ni-Zn ferrite core and CdS shell in a single material with tuneable fluorescence and magnetic properties, have been proposed by the seed mediated aqueous growth process. The shell particle thickness and core of nanostructures were precisely tuned. Current work exhibits the comparative study of core@shell multifunctional nanostructures where core being annealed at two different temperatures. The core@shell nanostructure formation was confirmed by complementary structural, elemental, optical, magnetic and IR measurements. Optical and magnetic characterizations were performed to study elaborative effects of different structural combinations of core@shell nanostructures to achieve best configuration with high-luminescence and magnetic outcomes. The interface of magnetic/nonmagnetic NiZnFe2O4/CdS nanostructures was inspected. Unexpectedly, in some of the core@shell nanostructures presence of substantial exchange-bias was observed in spite of the non-magnetic nature of CdS QDs which is clearly an “optically-active” and “magnetically-inactive” material. Presence of “exchange-bias” was confirmed by the change in “magnetic-anisotropy” as well as shift in susceptibility derivative. Finally, successful formulation of stable and efficient core@shell nanostructures achieved, which shows no exchange-bias and shift. Current findings suggest that these magneto-fluorescent nanostructures can be used in spintronics; and drug delivery-diagnosis-imaging applications in nanomedicine field.


Wear ◽  
2019 ◽  
Vol 424-425 ◽  
pp. 216-222 ◽  
Author(s):  
Weidi Kong ◽  
Dekun Zhang ◽  
Qing Tao ◽  
Kai Chen ◽  
Jian Wang ◽  
...  

2018 ◽  
Vol 19 ◽  
pp. 01035 ◽  
Author(s):  
Damian Burzyński ◽  
Damian Głuchy ◽  
Maksymilian Godek

The paper deals with the subject of influence of the Quick Charge technology on the parameters of the charging process of lithium-ion cells. Tests of lithium-ion cell parameters during the charging process were performed at three different temperatures using conventional and accelerated charging. Also, the following paper comprises conclusions related to the conducted tests.


2016 ◽  
Vol 122 (4) ◽  
Author(s):  
Majid Shamsipour ◽  
Zahra Pahlevani ◽  
Mohsen Ostad Shabani ◽  
Ali Mazahery

2017 ◽  
Vol 23 (2) ◽  
pp. 362-369 ◽  
Author(s):  
Michael Cloots ◽  
Livia Zumofen ◽  
Adriaan Bernardus Spierings ◽  
Andreas Kirchheim ◽  
Konrad Wegener

Purpose For geometries exhibiting overhanging surfaces, support structures are needed to dissipate process heat and to minimize geometrical distortions attributed to internal stresses. The use of support structures is often time- and cost-consuming. For this reason, this study aims to propose an approach which minimizes the use of such structures. Design/methodology/approach For minimizing the use of support structures, process parameters in combination with a contour-like exposure strategy are developed to realize support-less overhanging structures of less than 35°. These parameters are implemented in a shell-core strategy, which follows the idea of applying different processing strategies to the critical (overhanging) shell and the uncritical core of the part. Thereby, the core is processed with standard parameters, aiming a dense material. On the critical shell, optimized processing parameters are applied, reaching good results in terms of surface quality, especially at extreme overhang situations. Findings The results show that the selective laser melting (SLM) technology is able to realize support-less overhanging surfaces by choosing suitable scan strategies and process parameters. Particularly good results are always obtained when the exposure direction of the shell is parallel to the contour of the sample. Originality/value The validity of the results is demonstrated through the successful reproduction of the build strategy on two commercial SLM machines, reaching support-free builds of surfaces with an angle to the horizontal of less than or equal to 30°.


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