Acta Metallurgica Slovaca

AMS online

Year 2008

Visits: 85892530
AMS now reading: 1

Year 2008 No 2

Zifčák P., Brziak P., Balog M., Bošanský J., Srnka M.

THE INFLUENCE OF CREEP CONDITIONS TO MICROSTRUCTURE EVOLUTION AND SUGESTION OF PRECIPITATION CHANGES ASSESSMENT IN THE T24 STEEL

Keywords: steel T24|precipitation|carbides|

No 2 (2008), p. 195-208

mag01.pdf (463 kB)

mag01_eng.txt (2 kB)

Seidlerová J., Valášková M., Šustai O., Lešková J.

PHASE AND MORPHOLOGICAL CHARACTERISTICS OF METAL-BEARING MICROPARTICLES

Keywords: Fine grained metal-bearing wastes|Phase and morphology metallurgical wastes|

No 2 (2008), p. 209-223

mag02.pdf (2 MB)

mag02_eng.txt (2 kB)

Michalek K., Morávka J., Gryc K.

MODELLING OF TRANSFER PROCESSES IN GAS LADLE BUBBLING AND THEIR MATHEMATICAL IDENTIFICATION BY L-TRANSFORMATION

No 2 (2008), p. 224-232

mag03.pdf (278 kB)

mag03_eng.txt (2 kB)

Gulová L., Zemko M., Vlado M., Lászlo T.

SIMULATION OF PRODUCTION OF SELECTION DEFECTS IN ROLLING-PROCESS

No 2 (2008), p. 233-239

mag04.pdf (1 MB)

mag04_eng.txt (2 kB)

Nohavica D., Gladkov P., Jarchovský Z., Zelinka J.

DEFECT STRUCTURE MODIFICATIONS BY POROUS InP AND NON-IZOPERIODICAL HETEROJUNCTIONS GROWTH ON MICROPORES CONTAINING InP AND GaP

No 2 (2008), p. 240-246

mag05.pdf (346 kB)

mag05_eng.txt (2 kB)

Donič T., Martikán M.

EVALUATION OF RESULTS OF COMPRESSION AND TENSILE ANALYSIS OF COMPACTS ON THE BASE OF 1 µM ALUMINIUM POWDER

No 2 (2008), p. 247-256

mag06.pdf (289 kB)

mag06_eng.txt (2 kB)

Bidulská J., Bidulský R., Kvačkaj, T., Bardi F., Evangelista E.

FORMABILITY EVALUATION OF ALUMINIUM ALLOY BY MEANS OF TORSION TEST AT LOW STRAIN RATE

Keywords: aluminium alloy|torsion test|formability|

No 2 (2008), p. 257-262

mag07.pdf (179 kB)

mag07_eng.txt (2 kB)

Blach J., Ševc P., Výrostková A.

INFLUENCE OF HYDROGEN ON STRENGTH AND FAILURE OF DISSIMILAR WELD JOINT OF Cr-Mo,V STEELS FOR ENERGY EQUIPMENTS AT TENSILE STRAIN

Abstract
The influence of hydrogen on strength and failure of dissimilar weld joint of the two creep resistent steels with different chemical composition (9Cr-1Mo,V and 0,5Cr-0,5Mo,V) welded by arc welding after tensile strain tests at ambient temperature (+20 °C) was investigated.
Hydrogen presence in weld joint decreases notch strength (Rmv) and reduction area (Zv) in both the heat affected zone (HAZ) and welding metal (WM) at tensile straining (+20 °C) in the following order: 1. HAZ 0,5Cr-0,5Mo,V (STN15 128), 2. Weld metal T24 (2,5Cr-0,5Mo,V,Ti,B), 3. HAZ 9Cr-1Mo,V (P91).
Changes in appearance of fracture modes and mechanism of failure, induced by presence of hydrogen in dissimilar weld joint by means of fractography analyses of fracture surfaces of the HAZ and WM were observed. Ductile failure by dimpling at absence of the hydrogen changes to brittle cleavage failure caused by presence of hydrogen.
It was confirmed that nucleation of voids in tempered martensite steels at usual tensile load conditions predominantly occurs by separation of carbide/matrix interfaces. Voids initiate and grow preferentially around the large particles, later their coalescence with the voids around small particles between the crack tip and large voids leads to the final failure consisting of the large and small dimples.
The hydrogen in weld joint initiates a “brittle fracture” and cleavage (quasi-cleavage) on the carbide/matrix interfaces and decreases energy of the crack propagation. The mode of failure of the weld joint after hydrogen charging depends on the microstructure, size and distribution of particles (carbides) in different parts of the weld joint (HAZ, WM).

No 2 (2008), p. 263-274

mag08.pdf (397 kB)

mag08_eng.txt (2 kB)

Sučik G., Hršak D., Fedoročková A, Lazić L.

THE PRELIMINARY CHARACTERIZATION OF SERPENTINITE FROM LJESKOVAC LOCALITY IN CROATIA

No 2 (2008), p. 275-280

mag09.pdf (193 kB)

mag09_eng.txt (839 B)

Mišičko R.

PHYSICAL – METALLURGICAL FUNDAMENTAL CONCEPT OF CRACKING OF CONTINUOUSLY CAST PRODUCTS

No 2 (2008), p. 281-285

mag16.pdf (53 kB)