Acta Metallurgica Slovaca

AMS online

Year 2006

Visits: 85152947
AMS now reading: 1

Year 2006 No 2

Polak K.

Keywords:

No 2 (2006), p. 111-118

mag01.pdf (451 kB)

mag01_eng.txt (257 B)

Kiatgamolchai S., Parinyataramas J., Nilpairach S., Thueploy A., Wanichsampan J., Min G.

THERMOELECTRIC PROPERTIES OF -FESI2 PREPARED BY THE MECHANICAL ALLOYING TECHNIQUE AND PRESSURELESS SINTERING

No 2 (2006), p. 119-127

mag02.pdf (851 kB)

mag02_eng.txt (2 kB)

Ševčík A., Ševčíková J.

ANALYSIS OF THE REDUCTION OF AREA VALUES DROP AT HIGH TEMPERATURE TESTING OF LOW CARBON STEELS IN THE AS-CAST STATE

No 2 (2006), p. 128-138

mag03.pdf (777 kB)

mag03_eng.txt (2 kB)

Mišičko R., Masek V., Sojko M.

QUALITY OF SOLIDIFIKACION STRUCTURE IN CONTINUOUSLY CAST SLABS FOR DIFFERENT CASTING RATES

No 2 (2006), p. 139-146

mag04.pdf (819 kB)

mag04_eng.txt (1 kB)

Wangyao P., Polsilapa S., Homkrajai W., Krongtong V., Panich N.

EFFECT OF RE-HEAT-TREATMENTS ON MICROSTRUCTURES IN CAST NICKEL-BASE SUPERALLOY TURBINE BLADE, UDIMET 500

Abstract
This work has an aim to refurbish the microstructure of superalloy after long-term service at elevated temperature by simple re-heat treatment. The microstructures of cast polycrystalline nickel base superalloy, Udimet 500, operated by Electricity Generating Authority of Thailand (EGAT) for long-term services (50000 hours) were investigated by scanning electron microscopy (SEM) after different re-heat-treatment conditions. The influence of various solution and aging heat treatments on the dissolution and precipitation behaviors of ?’ in the nickel base superalloy was studied and analyzed. It was found that microstructure of the exposed specimen after long-term service could be nearly recovered by a re-solution treatment followed by two-step aging treatments. During solution treatment, the coarse carbides and gamma prime precipitates were partially dissolved into the matrix. Then specimens were heat treated through series of aging resulting in uniformly dispersed precipitation of gamma prime particles, which is more uniform than those in the long-term exposed microstructure. Generally, good high-temperature strength in most nickel-base superalloys could be expected from the presence of a high volume fraction of small precipitates of the ??-phase (Ni3(Al,Ti)). However, it was also found that the higher solution annealing temperature resulted in less volume fraction of coarse gamma prime precipitates and less homogeneous in microstructure than the lower one. Furthermore, the longer secondary aging time results in negative effect on microstructure due to the less density of very fine ?’ precipitated particles, which were re-dissolved again.

No 2 (2006), p. 147-153

mag05.pdf (872 kB)

mag05_eng.txt (2 kB)

Lothongkum G., Ratanamahasakul S., Wangyao P.

THE RELATIONSHIP BETWEEN HEAT-TREATED MICROSTRUCTURES AND MECHANICAL PROPERTIES IN CAST IRON-BASE ALLOY

No 2 (2006), p. 154-166

mag06.pdf (1 MB)

mag06_eng.txt (2 kB)

Kubiński W., Krawczyk K.

APPLICATION OF EVOLUTIONARY ALGORITHMS FOR OPTIMIZATION OF PRODUCTION SCHEDULE IN FOUNDRY

Keywords: evolutionary algorithms|optimization of production schedule|operational planning in foundry|

No 2 (2006), p. 167-178