Dilatometric analysis tool steel X153CrMoV12

Fulltext (.pdf 568 kB)

https://doi.org/10.52651/sam.a.2021.1.14-18

Autor: Michal KRBAŤA, Róbert CÍGER

In: Science & Military

ISSN: 2453-7632

Ročník: 16

Číslo: 1

Strany: 14 - 18

Rok vydania: 2021

Vydavateľ: Akadémia ozbrojených síl generála Milana Rastislava Štefánika, Liptovský Mikuláš

Abstrakt: The article deals with phase transformations and austenitizing behavior of the X155CrMoV12 tool steel. Dilatation analyses of a series of samples were performed at various cooling rates, chosen in the range from 10 °C·s-1 to 0.1 °C·s-1. Acquired experimental data were used for evaluation of dilatometric curves in order to map the temperature ranges of phase transformations of the austenite to pearlite, bainite or martensite. All experimental samples from dilatometric analyses were then subjected to microstructural analyses and hardness measurements to characterize the microstructure and hardness for every tested heat treatment regime. The second part of this article, entitled "EXPERIMENTAL DETERMINATION OF CONTINUOUS COOLING TRANSFORMATION DIAGRAM FOR HIGH STRENGTH STEEL X153CRMOV12", deals with these analyses of the cooling curve microstructure.

Kľúčové slová: ARA diagram; Tool steel; Dilatometry; Compression test.

Citácia:
KRBAŤA, Michal a Róbert CÍGER. Dilatometric analysis tool steel X153CrMoV12. In: Science & Military [online]. Liptovský Mikuláš: Akadémia ozbrojených síl generála Milana Rastislava Štefánika, 2021, 16 (1), s. 14-18. ISSN: 1336-8885 (print).
ISSN: 2453-7632 (online). Dostupné na internete: https://doi.org/10.52651/sam.a.2021.1.14-18

Stress prediction analysis during hot working of 100MnCrW4 steel

Fulltext (.pdf 856 kB)

https://doi.org/10.52651/sam.a.2021.1.25-31

Autor: Maroš ECKERT

In: Science & Military

ISSN: 2453-7632

Ročník: 16

Číslo: 1

Strany: 25 - 31

Rok vydania: 2021

Vydavateľ: Akadémia ozbrojených síl generála Milana Rastislava Štefánika, Liptovský Mikuláš

Abstrakt: This paper deals with the analysis and the possibility of using a constitutive model based on the Arrhenius equationfor tool steel 100MnCrW4. Experimental measurements were performed on a DIL 805 dilatometer in the range of strain rate 0.001 s-1 for 10 s -1 and temperature from 800 to 1200 °C. Using constitutive equations, material parameters and activation energy were derived, which can be subsequently applied to other models selated to hot behavior of deformation. The experimental data were compared to the ones obtained by the predictive model with the correlation coefficient R = 0.97885 and the parameter MAPE = 17.28 % which means a very good level of prediction.

Kľúčové slová: Tool steel; Hot working; True stress; Dilatometry; Arrhenius equation.

Citácia:
ECKERT, Maroš. Stress prediction analysis during hot working of 100MnCrW4 steel. In: Science & Military [online]. Liptovský Mikuláš: Akadémia ozbrojených síl generála Milana Rastislava Štefánika, 2021, 16 (1), s. 25-31. ISSN: 1336-8885 (print). ISSN: 2453-7632 (online). Dostupné na internete: https://doi.org/10.52651/sam.a.2021.1.25-31

Experimental determination of continuous cooling transformation diagram for high strength steel X153CrMoV12

Fulltext (.pdf 616 kB)

https://doi.org/10.52651/sam.a.2021.1.19-24

Autor: Michal KRBAŤA, Róbert CÍGER

In: Science & Military

ISSN: 2453-7632

Ročník: 16

Číslo: 1

Strany: 19 - 24

Rok vydania: 2021

Vydavateľ: Akadémia ozbrojených síl generála Milana Rastislava Štefánika, Liptovský Mikuláš

Abstrakt: The article is a continuation of the article ,DILATOMETRIC ANALYSIS OF COOLING CURVES FOR HIGH STRENGTH STEEL X153CrMoV12”, which deals with the phase transformations of tool steel X153CrMoV12. The experimental data obtained was used to evaluate the resulting CCT diagram, which consists of seven dilation curves. All experimental samples from dilatometric analyses were then subjected to microstructural analysis and hardness measurements to characterize the microstructure and hardness for each heat treatment mode tested. AFM microscopy was also used to study the carbides present in steels and their size and shape for all selected cooling modes.

Kľúčové slová: Dilatometry; Tool steel; Cooling rate; Martensite; CCT diagram.

Citácia:
KRBAŤA, Michal a Róbert CÍGER. Experimental determination of continuous cooling transformation diagram for high strength steel X153CrMoV12. In: Science & Military [online]. Liptovský Mikuláš: Akadémia ozbrojených síl generála Milana Rastislava Štefánika, 2021, 16 (1), s. 19-24. ISSN: 1336-8885 (print). ISSN: 2453-7632 (online). Dostupné na internete: https://doi.org/10.52651/sam.a.2021.1.19-24

The role and the risks of explosive ordnance decontamination in Hungary

Fulltext (.pdf 666 kB)

https://doi.org/10.52651/sam.a.2021.1.32-42

Autor: István EMBER

In: Science & Military

ISSN: 2453-7632

Ročník: 16

Číslo: 1

Strany: 32 - 42

Rok vydania: 2021

Vydavateľ: Akadémia ozbrojených síl generála Milana Rastislava Štefánika, Liptovský Mikuláš

Abstrakt: The work of the experts of explosive ordnance disposal is very demanding in Hungary. Thousands of explosive remnants of war are still waiting for disarming in the soil. This public duty demands highly trained professionals who are able to meet the requirements of this lethal profession. The statistics are important to receive a complete picture about the background of projectiles and bombs. These military ordnances endanger everybody’s live in their close distance. To understand the features of these dangerous devices, first the threats hidden inside their main parts must be identified. This may help us to make the explosive ordnance disposal tasks safer and to understand the possibilities during render safe procedures.

Kľúčové slová: Disarming; Decontamination; Explosive ordnance disposal; EOD; Explosives; Threat.

Citácia:
EMBER, István.The role and the risks of explosive ordnance decontamination in Hungary. In: Science & Military [online]. Liptovský Mikuláš: Akadémia ozbrojených síl generála Milana Rastislava Štefánika, 2021, 16 (1), s. 32-42. ISSN: 1336-8885 (print). ISSN: 2453-7632 (online). Dostupné na internete: https://doi.org/10.52651/sam.a.2021.1.32-42