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Year 1997 No 3

Štepánek A., Vydarený V.
ELECTROSLAG REMELTING CR-NI-MO ALLOY STEELS
Keywords:
No 3 (1997), p. 191-195
  mag01.pdf (108 kB)
mag01_eng.txt (1 kB)  

Smolková M.
NEW TRENDS IN UTILIZATION OF GRINDERS FOR ABRASION RESISTANCE CASTING PRODUCTS
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No 3 (1997), p. 196-202
  mag02.pdf (157 kB)
mag02_eng.txt (1 kB)  

Seriš J., Pavlík J.
ON THE HEAVY FORGING FROM CONSTRUCTIONS STEELS
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No 3 (1997), p. 203-210
  mag03.pdf (223 kB)
mag03_eng.txt (2 kB)  

Bezecný J.
CONTRIBUTION TO THE SOLUTION OF PROBLEMS CONNECTED WITH THE FORMATION OF INTERNAL DEFECTS IN LARGE-SIZE FORGINGS
Abstract
The conformity result of ultrasonic tests is one of the main quality criteria of large-size free forgings.
The ultrasonic test is specified for both quantity and size checking of internal defects in material where all defects of non-entirety nature are not permissible. In general, it is necessary to complete this test with a complex metallographical analysis in order to specify them in more details.
Presented contribution is specialized in more detailed describtion one of typical internal discontinuities in large-size forgings that was identified generally in the literature as "cracks in segregates".
The cracks in segregates are very similar to flakes from the morphological point of view when macroscopically estimated so they can easily cause a confusion.
The doubtless differentiation /resolution/ is possible only by means of the electron microscopy.
Based on long-term observation of two carbon steel types and medium alloyed steel it was found that major of discontinuities detected by the ultrasonic test is of non-entirety nature being located in interdendritic area. Macroscopically they looked like bright areas of various shapes. In any case no dominant fracture pattern qualifying them as "cracks" was observed on their surface. These defects were characterized by so-called free surfaces (i.e. never contacted) that are typical for primary metallurgical defects of a microshrinkage cavity type or other holes which were extended only but not connected in the time of shaping.
Because of this reason the name for their identification was proposed as "discontinuities in segregates".

Keywords:
No 3 (1997), p. 211-217
  mag04.pdf (162 kB)
mag04_eng.txt (2 kB)  

Kuzmiak Š., Solovičová J.
THE INFLUENCE OF HEAT TREATMENT PARAMETERS ON PROPERTIES OF MN AS-CAST AUSTENITIC STEEL
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No 3 (1997), p. 218-224
  mag05.pdf (179 kB)
mag05_eng.txt (1 kB)  

Krušinský J., Minárik A.
INFLUENCE OF HEAT TREATMENT CONDITIONS ON CHROMIUM ALLOYED CAST IRON PROPERTIES
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No 3 (1997), p. 225-231
  mag06.pdf (140 kB)
mag06_eng.txt (1 kB)  

Jančarik M., Vydrnák J., Štrauch J.
WELDED-ON LAYERS METALLURGICAL ROLLS
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No 3 (1997), p. 232-235
  mag07.pdf (170 kB)
mag07_eng.txt (942 B)