Metallurgy and Foundry Engineering
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ISSN 1230-2325
e-ISSN: 2300-8377
Issue Date
2016
Volume
Vol. 42
Number
No. 4
Description
Journal Volume
Metallurgy and Foundry Engineering
Vol. 42 (2016)
Projects
Pages
Articles
Detection of nitrates(V) and sulfates(VI) by UV-Vis spectrophotometry method in used green sand bonded by bentonite with modified starch addition
(Wydawnictwa AGH, 2016) Grabowska, Beata; Kurleto-Kozioł, Żaneta; Szymański, Łukasz; Kaczmarska, Karolina; Bobrowski, Artur
The research results (SEM, UV-Vis) that contain a part of the work connected with determining the influence of a modified starch addition on the physical and chemical property changes of green sands (including the emission levels of harmful substances from the used molding sands formed as a result of the liquid metal pouring of molds) are presented in this paper. A surface analysis (SEM) was performed for the fresh molding sands and used molding sands with and without modified starch samples. On the bases of the received microscopic images, the impact of the temperature factor on the morphology of the molding sand samples after the liquid metal pour- ing process are assessed. In the second part of the performed work on the UV-Vis research, eluates from two used molding sands (green sand [sand number 1] and green sand with the addition of a modified starch [sand number 2]) were tested for nitrate and sulfate content. In order to deter- mine whether the level of nitrate and sulfate elusion from the used molding sands is permissible, the received results were compared with the Minister of Environment’s regulations concerning the requirements of surface waters used for supplying the population with potable water.
Characterization of microstructure and mechanical properties of laser-welded stainless steels
(Wydawnictwa AGH, 2016) Koclęga, Damian; Radziszewska, Agnieszka; Kąc, Sławomir; Zowczak, Włodzimierz; Dębowska, Aleksandra; Jędrusik, Mateusz; Petrzak, Paweł
This work presents the laser welding of dissimilar X12CrCoWVNbN12-2-2 and X10CrNi18-10 steels. This system is of interest, as laser welding offers new flexibility in the joining of metals and laser welds (LWs) and are usually of high quality, they are obtained only after the optimization of process parameters. The aim of the work was to investigate the microstructure, chemical composition, and hardness changes of laser-welded steels. After laser welding, two zones were generated in the processed materials: a fusion zone and a heat-affected zone. Due to solidification, a refinement of the microstructure occurred in the fusion zone. Examinations of the chemical composition of particular melted areas showed the occurrence of Nb-rich precipitations. The laser welding of steels led to increased hardness in the fusion zone (about 240–530 HV0.3).
Microstructure and texture welds of 15-7Mo steel after heat treatment
(Wydawnictwa AGH, 2016) Ziewiec, Aneta; Zielińska-Lipiec, Anna; Witkowska, Małgorzata
This paper presents the results of determining the effect of heat treatment after welding X8CrNiMoAl15-7-2 steel (commercial name: PH 15-7Mo steel) on the microstructure and texture of the welds. XRD studies showed the presence of the two phases in the welds of 15-7Mo steel, i.e., δ ferrite and austenite. Annealing at a temperature of 400°C/1 h and 550°C/1 h results in changes of the intensities for individual peaks derived from austenite and ferrite. Microstructure investigations carried out by LM and TEM indicated that the austenite and δ ferrite coexist in the microstructure of 15-7Mo steel in as-welded condition. Annealing at a temperature range of be- tween 400–620°C after welding causes small changes in the microstructure. The hardness of the welds after annealing in that temperature range increases.
Microstructure evaluation of laser-welded 600 nickel alloy
(Wydawnictwa AGH, 2016) Tuz, Lechosław
This paper presents the results of a microstructure analysis of a laser butt-welded 600 nickel alloy. A microstructure evaluation of the joint is carried out with the use of light microscopy and scan- ning electron microscopy. The results indicate a phase γ with some particles in the grain boundaries in the base metal. In the weld, a cellular-dendritic structure was observed.