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Hardness

Chulalongkorn University

Publication Year

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Full-Text Articles in Engineering

Effect Of Silicon On Subcritical Heat Treatment Behavior And Wear Resistance Of 16 Wt% Cr Cast Iron With 2 Wt% Mo, P. Kosasu, S. Inthidech, P. Srichareonchai, Y. Matsubara Dec 2012

Effect Of Silicon On Subcritical Heat Treatment Behavior And Wear Resistance Of 16 Wt% Cr Cast Iron With 2 Wt% Mo, P. Kosasu, S. Inthidech, P. Srichareonchai, Y. Matsubara

Journal of Metals, Materials and Minerals

Effects of Si content on the hardness, decomposition of austenite and abrasive wear resistance during subcritical heat treatment of hypoeutectic 16 wt% Cr -2 wt% Mo cast irons were investigated. The hypoeutectic 16 wt%Cr-2wt% Mo cast irons with 0.5-2.0 wt% Si were prepared. The as-cast specimens were heated up to subcritical temperatures at 50 K intervals from 673K for 14.4 ks ,28.8 ks and 43.2 ks and then, cooled to the room temperature by fan air cooling. In the as-cast state, the hardness increased gradually as Si content increased to 1.5 wt% and then decreased rapidly. The size and the …


Three-Body-Type Abrasive Wear Behavior Of 26% Cr Cast Iron With Molybdenum, A. Chooprajong, P. Sricharoenchai, S. Inthidech, Y. Matsubara Jul 2012

Three-Body-Type Abrasive Wear Behavior Of 26% Cr Cast Iron With Molybdenum, A. Chooprajong, P. Sricharoenchai, S. Inthidech, Y. Matsubara

Journal of Metals, Materials and Minerals

Hypoeutectic 26 wt% Cr cast irons without and with Mo were prepared in order to investigate their abrasion wear resistance. The annealed specimens were hardened from 1323 K (As-H) and then tempered at three levels of temperatures between 673 and 823 K for 7.2ks, the temperature giving the maximum hardness (HTmax), lower temperature than that at HTmax (L-HTmax ) and higher temperature than that at HTmax (H-HTmax). The abrasive wear resistance was evaluated using Rubber Wheel abrasion test (three-body-type). It was found that hardness and volume fraction of retained austenite (V) in the heat-treated specimens varied with the Mo content …


Effect Of Solution Annealing Temperature On Structure And Mechanical Properties Of En Aw 2024 Aluminium Alloy, M Fujda, R Mišičko, L Rusňáková, M Sojko Jul 2007

Effect Of Solution Annealing Temperature On Structure And Mechanical Properties Of En Aw 2024 Aluminium Alloy, M Fujda, R Mišičko, L Rusňáková, M Sojko

Journal of Metals, Materials and Minerals

The effect of solution annealing temperature on the change of microstructural and mechanical properties of EN AW 2024 aluminium alloy was investigated using a metallographic analysis, Vickers hardness measurement and tensile test. An intensive growth of solid solution grains was the result of the increase of solution annealing temperature by the finely dispersed particles dissolved during applied annealing process. The role of these finely dispersed particles was to inhibit the recrystallization process and grain growth of solid solution matrix through its pinning effect on the migrated solid solution grain boundaries. Observed changes of the microstructure involved the strength decline and …


The Relationship Between Reheat-Treatment And Hardness Behaviour Of Cast Nickel Superalloy, Gtd-111, P Wangyao, V Krongtong, P Tuengsook, W Hormkrajai, N Panich Jul 2006

The Relationship Between Reheat-Treatment And Hardness Behaviour Of Cast Nickel Superalloy, Gtd-111, P Wangyao, V Krongtong, P Tuengsook, W Hormkrajai, N Panich

Journal of Metals, Materials and Minerals

he microstructure of cast polycrystalline nickel base superalloy, GTD-111, operated for long-term services were investigated by SEM after different re-heat-treatment conditions. It was found that the exposed specimen after long-term service could be recovered in some extent by re-solution treatment followed by two-step aging treatment. The obtained dispersed precipitation of gamma prime particles was more uniform than those of the long-term exposed microstructure. The results showed that the couple of the lower (1125°C) and/or higher (1175°C) solution annealing temperatures resulted in less total volume fraction of coarse gamma prime precipitates and less homogeneous distribution in microstructure than the medium (1150°C) …


Multilayered Systems Of Nanostructured Tib2 Thin Films And Its Mechanical Properties, N Panich, P Wangyao, S Hannongbua, P Sricharoenchai, S Sun Jul 2006

Multilayered Systems Of Nanostructured Tib2 Thin Films And Its Mechanical Properties, N Panich, P Wangyao, S Hannongbua, P Sricharoenchai, S Sun

Journal of Metals, Materials and Minerals

This study focuses on the development of single and multilayer TiB2 coatings with Ti interlayer with the aim of improving the mechanical integrity of the coating-substrate system. The nanostructured TiB2 thin films and multilayered coatings were deposited on high speed steel substrates by magnetron sputtering. The resultant coating systems were evaluated with respect to microstructure, fractured cross-section and fundamental properties such as cross-sectioned fracture, surface roughness, hardness, modulus and coating adhesion to the substrate. It was found that the adhesion strength of TiB2 coating to HSS substrate could be significantly enhanced in the multilayer system, and by a proper combination …