Engineering Commons^™

تأثير متغيرات معالجة Rra الحرارية على الخواص الميكانيكية لسبيكة الألمنيوم عالية المقاومة 7075, Mohammad Nefawy, Fouad Dhahya

Palestine Technical University Research Journal

Retrogression and Re-Aging Heat Treatment improves tensile and wear resistance of aluminum alloys, to study the effect of Retrogression temperature and Retrogression time on the tensile strength, Toughness Impact and Hardness of 7075 aluminum alloy, we have applied in this research Retrogression treatments at different temperatures are 150°C, 180°C, 240°C and 370°C for 15 min, 30 min and 90 min. When the retrogression temperature was 180°C for 30 min, the alloy has reached its highest tensile strength and hardness it was respectively 586 Mpa and 165 HB, While the alloy has reached its highest impact toughness it was 32.7 J\Cm2, …

Displaced Hardness Peak Phenomenon In Heat-Affected Zone Of Welded Quenched And Tempered Em812 Steel, Druce P. Dunne, W Pang

Faculty of Engineering and Information Sciences - Papers: Part A

Investigations of microstructural and hardness gradients in the heat-affected zone (HAZ) of quenched and tempered (Q&T) steels have indicated that peak hardness does not occur in the grain-coarsened heat-affected zone (GCHAZ) adjacent to the fusion boundary, which is typical of ferritic steels, but corresponds more closely to the grain-refined region (GRHAZ). This phenomenon, the displaced hardness peak (DHP) effect, is considered to arise when the hardenability of the steel is high enough to result in the same microstructure in the GC and GR heat-affected zones, except for significant refinement of the microstructure of the GRHAZ, which increases the hardness and …

A Study Surface Layer And Hardness Produced By Induction Hardened S45c Steel, Alain Parisianto, Rosfian Dahar, Huijun Li, Syamsul Hadi

Faculty of Engineering and Information Sciences - Papers: Part A

A cylinder of Carbon Steel S45C with a ferrite and pearlite structure was analysed to improve the hardness and surface layer as well as the toughness. Accordingly, it is important to undertake a heat treatment process for the hardness and surface layer of this steel. The heat teatment process was carried out using induction heating with five different temperatures of 800°C, 900°C, 1000°C, 1100°C and 1200 °C followed by water quenching with certain cooling speed. The chemical compositions and microstructures of these samples were characterized by spectrometer and optical microscopy. The microhardness of the samples was measured and the surface …

Hardness-Tensile Property Relationships For Haz In 6061-T651 Aluminum, P A. Stathers, Alan K. Hellier, R P. Harrison, M I. Ripley, John Norrish

Faculty of Engineering and Information Sciences - Papers: Part A

High-strength aluminum is used extensively in industry, with welding being a widely used fabrication method. This work focuses on welding of 6061-T651 aluminum and establishment of the hardness-tensile properties relationship in the heat-affected zone (HAZ) of a gas metal arc weld using 4043 filler material. Test welds were prepared from 12.7-mm-thick plate with a single-V weld preparation. Base plate temperatures were measured with an array of eight embedded thermocouples during welding, relating temperature to properties at intervals from the weld. Through-thickness slices 1.7 mm thick were removed, by electric discharge machining, from the plate parallel to the weld at 2-mm …

Treatment Technology Validation For Water Softening Technology, Caitlin Brown, Nathan Dillon, Kevin Tweeten, Peixi Yan, Kayla Lester, Tim Lewis

Senior Design

MT Hard Water of Montana Tech of the University of Montana submits Task 3: Treatment Technology Validation for Water Softening Technology as an entry into the 2012 WERC Environmental Design Contest.

Currently, there are several commercially available technologies that treat water hardness. The objective of this project is to develop a strategy to evaluate and validate different water hardness treatment technologies. MT Hard Water (MTHW) has studied several technologies including: electromagnetic water treatment, ion exchange, and reverse osmosis. For validation purposes, an electromagnetic water treatment system (ScaleRID) was selected according to the WERC task description.

Effect Of The Austenitising Heat Treatment On The Microstructure And Hardness Of Martensitic Stainless Steel Aisi 420, Lilian D. Barlow, Madeleine Du Toit

Faculty of Engineering and Information Sciences - Papers: Part A

The effect of austenitizing on the microstructure and hardness of two martensitic stainless steels was examined with the aim of supplying heat-treatment guidelines to the user that will ensure a martensitic structure with minimal retained austenite, evenly dispersed carbides and a hardness of between 610 and 740 HV (Vickers hardness) after quenching and tempering. The steels examined during the course of this examination conform in composition to medium-carbon AISI 420 martensitic stainless steel, except for the addition of 0.13% vanadium and 0.62% molybdenum to one of the alloys. Steel samples were austenitized at temperatures between 1000 and 1200 C, followed …

Hardness And Microstructural Gradients In The Heat Affected Zone Of Welded Low-Carbon Quenched And Tempered Steels, W Pang, N Ahmed, D Dunne

Faculty of Engineering and Information Sciences - Papers: Part A

This paper concentrates on the form of the hardness gradient in the heat affected zones (HAZs) produced by submerged arc welding of two low-carbon Q & T steels. The results show unequivocally that the gradient differs from that found in steels of lower carbon equivalent in that the peak HAZ hardness is displaced from the grain coarsened heat affected zone (GCHAZ) into the grain refined heat affected zone (GRHAZ). Weld thermal cycle simulation has been used to confirm the results obtained from actual welds and to clarify the cause of this unexpected phenomenon.