Wyniki wyszukiwania - BazTech

1

Long-term Annealing of NiCrAlY LENS Coating on 316L Steel

Szymański Krzysztof K.

Archives of Foundry Engineering

|

2022

|

Vol. 22, iss. 4

116--120

EN

This article presents the results of a research on the behavior of NiCrAlY coating obtained by the LENS method on austenitic stainless steel type 316L under long-term annealing conditions at 1000°C for 25, 100 and 250 hours. The morphology of the NiCrAlY layer as a function of annealing time and temperature was characterized. The chemical composition and distribution of alloying elements were evaluated using scanning microscopy and micro-area chemical composition analysis. It was revealed that NiCrAlY coatings deposited by LENS method are characterized by good metallurgical quality. The long-term annealing of the NiCrAlY coating led to microstructural changes in the form of the disappearance of the original dendritic structure and the formation of a solid solution of nickel with chromium and a small amount of aluminum, as well as chromium α-Cr precipitates and Ni-Y-type phases. The effect of increasing iron concentration in the coating due to diffusion-to-core processes was also found.

2

Computer-assisted analysis of changes in the microstructure of P92 steel after exposure at elevated temperature

Zieliński A., Dobrzański J., Golański G., Sroka M.

Archives of Materials Science and Engineering

|

2014

|

Vol. 65, nr 2

77--86

EN

Purpose: The purpose of the work was to analyse the components of X10CrWMoVNb9-2 (P92) steel in initial state and after long-term annealing for up to 100,000 h at 600 and 650°C. Design/methodology/approach: The material for investigation was X10CrWMoVNb9-2 (P92) steel in the form of a Ø160x40mm tube. The images of microstructure were recorded using the scanning electron microscopy. The quantitative analysis of precipitates was carried out using the image analysis system NIKON EPIPHOT200 & LUCIA G v.5.03. Findings: The investigations of microstructure and the quantitative analysis of precipitates in the tested steel in initial state and after long-term annealing allowed the impact of temperature and time on stability of the microstructure of the tested steel to be evaluated. Practical implications: The presented method can be used for evaluation and qualification of structural changes in power station boiler components operating under creep conditions. Originality/value: The presented results of changes in the structure and in the precipitation processes are applied to evaluation of the condition of the elements in further industrial service.

3

Computer assisted evaluation of degree of exhaustion of T/P23 (2.25Cr-0.3Mo-1.6W-V-Nb) steel after long-term annealing

Sroka M., Zieliński A.

Archives of Materials Science and Engineering

|

2013

|

Vol. 64, nr 2

205--212

EN

Purpose: The method of image analysis and artificial intelligence methods in the evaluation of materials while working in creep conditions were proposed. The application of scanning electron microscopy in the correct assessment of the degree of exhaustion was of a demonstration character. Design/methodology/approach: For the material after long-term operation in the creep tests microstructure examination was performed in a scanning electron microscope. To assess the degree of exhaustion of the material, the computer program was used. Findings: The article demonstrates how to assess the state of the material using a computer program as an example of the application of computer methods for materials science. The verification was found to develop methodologies for assessing the correct level of exhaustion while working in steel material creep conditions. Practical implications: The presented method can be used for evaluation and qualification of structural changes in power station boiler components operating in creep conditions. Originality/value: The obtained results of changes in the mechanical properties, microstructure and in the precipitation processes are applied to the evaluating the condition of the elements in further industrial service.

4

Ddoświadczenia z zastosowania nowych stali do wytwarzania elementów kotłów na parametry nadkrytyczne

Dobrzański J., Zieliński A., Pasternak J., Hernas A.

Prace Instytutu Metalurgii Żelaza

|

2010

|

T. 62, nr 1

51-60

PL

W referacie przedstawiono charakterystyki nowych stali żarowytrzymałych stosowanych w budowie kotłów nadkrytycznych, w tym szczególnie wyniki badań cienko- i grubościennych złączy spawanych. Przedmiotem badań były niskostopowe stale bainityczne TP23 i TP24 oraz wysokostopowe martenzytyczne TP91, TP92, VM12 oraz austenityczna HR3C. Dokonano analizy doboru materiałów na przegrzewacze pary kotła nadkrytycznego. Przedstawiono charakterystyki struktury i właściwości mechanicznych w temperaturze pokojowej i podwyższonej materiałów podstawowych oraz złączy spawanych. Zweryfikowano zastosowane technologie spawania i oceniono przydatności badanych materiałów do określonych zastosowań.

EN

The paper presents characteristics of new creep resisting steels for boilers, and in particular the results of tests of thin- and heavy-walled welded joints. Low-alloy TIP23 and TIP24 steels, high-alloy T/P91, T/P92, VM12 and austenitic HR3C steels ivere subject to testing. Analysis of selection of the material for supercritical boiler steam superheater was conducted. Characteristics of the structure and mechanical properties at ambient and elevated temperature of basic materials and welded joints were presented. The applied technologies of welding were verified, moreover usability of the examined materials in specific applications was assessed.

5

The influence of long-term annealing on the microstructure of Elektron 21 magnesium alloy

Kiełbus A.

Inżynieria Materiałowa

|

2008

|

Vol. 29, nr 4

310-315

EN

Elektron 21 is a new magnesium based casting alloy for used to 200°C. The microstructural changes after long-term annealing at 520°C (2-48 h) and 350°C (500-5000 h) have been presented. For the microstructure observation, a OLYMPUS GX71 metallographic microscope and a HITACHI S-3400N scanning electron microscope were used. Quantitative examination was conducted using the Met-Ilo automatic image analysis program. The Elektron 21 alloy in as-cast condition is characterized by a solid solution structure a with precipitates of Mg12(Nd,Gd) intermetallic phase on grain boundaries. After annealing (solutioning) at 520°C a reduction of the number of Mgi2(Nd,Gd) phase precipitates was observed. Its area fraction falls with the extension of the treatment time from AA=6.55% (as cast state) to AA= 0.5% (24 h of treatment). Also, an increase of the solid solution a grain size was observed from A=649 um2 to J=3000 um2. After annealing at 350°C the precipitation of Mg41Nd5 phase was observed. Its area fraction falls with the extension of the treatment time from AA=3.55% (500 h) to AA=5.55 % (5000 h of treatment). The solid solution a grain size didn't change.

PL

Stop magnezu Elektron 21 jest nowym stopem przeznaczonym do pracy w temperaturze do 200°C. W artykule zaprezentowano zmiany mikrostruktury podczas długotrwałego wyżarzania w temperaturze 500°C (2-48 h) i 350°C (500-5000 h). Do badań mikrostruktury zastosowano mikroskop optyczny OLYMPUS GX71 oraz mikroskop elektronowy skaningowy HITACHI S-3400N. Ilościową ocenę mikrostruktury przeprowadzono z wykorzystaniem programu "Met-Ilo". Stop Elektron 21 w stanie lanym charakteryzuje się strukturą roztworu stałego z wydzieleniami fazy Mg12(Nd,Gd) na granicach ziaren. Po wyżarzaniu (przesycaniu) w temperaturze 520°C obserwowano zmniejszenie udziału objętościowego fazy Mg12(Nd,Gd) z poziomu AA=6,55% (stan lany) do poziomu AA=0,5% (po 24 h obróbki). Natomiast średnie pole powierzchni płaskiego przekroju ziarna roztworu stałego zwiększało się z A=649 um2 do A=3000 um2. Po wyżarzaniu w temperaturze 350°C obserwowano wydzielanie fazy Mg41Nd5. Jej udział objętościowy zwiększa się wraz z wydłużaniem czasu obróbki z AA=3,55% (po 500 h) do AA=5,55% (po 5000 h). Średnie pole powierzchni płaskiego przekroju ziarna roztworu stałego nie zmienia się.