Publication detail

Fracture behaviour of weld joints made of pearlitic and bainitic steel

VÁLKA, L. DLOUHÝ, I.

English title

Fracture behaviour of weld joints made of pearlitic and bainitic steel

Type

journal article - other

Language

en

Original abstract

The paper is concerned with microstructure evaluations and the hardness and fracture behaviour of welded joints made from cast bainitic Lo8CrNiMo steel and pearlitic rail steel of the type UIC 900A. The materials mentioned are predetermined for frogs of switches. The study is based mainly on microstructural observations and hardness measurements of the base materials, weld, and heat affected zone (HAZ). Dynamic fracture toughness was evaluated based on data from pre-cracked Charpy type specimens. The pearlitic UIC 900A steel and its HAZ had the lowest dynamic fracture toughness values and therefore the highest risk of brittle fracture. At application temperature range, this steel is on the lower shelf of the ductile-to-brittle transition, and the tempering in the HAZ did not affect the toughness substantially. The cast bainitic steel in the weld joint is characterized by higher toughness values compared to the pearlitic one, and a further increase in toughness may be expected in the HAZ. The weld zone itself is characterized by high scatter of toughness data; nevertheless, all the values are above the scatter band characterizing the pearlitic steel.

English abstract

The paper is concerned with microstructure evaluations and the hardness and fracture behaviour of welded joints made from cast bainitic Lo8CrNiMo steel and pearlitic rail steel of the type UIC 900A. The materials mentioned are predetermined for frogs of switches. The study is based mainly on microstructural observations and hardness measurements of the base materials, weld, and heat affected zone (HAZ). Dynamic fracture toughness was evaluated based on data from pre-cracked Charpy type specimens. The pearlitic UIC 900A steel and its HAZ had the lowest dynamic fracture toughness values and therefore the highest risk of brittle fracture. At application temperature range, this steel is on the lower shelf of the ductile-to-brittle transition, and the tempering in the HAZ did not affect the toughness substantially. The cast bainitic steel in the weld joint is characterized by higher toughness values compared to the pearlitic one, and a further increase in toughness may be expected in the HAZ. The weld zone itself is characterized by high scatter of toughness data; nevertheless, all the values are above the scatter band characterizing the pearlitic steel.

Keywords in English

welded joint; bainitic steel; pearlitic steel; dynamic fracture toughness; point crossing frog

Released

12.06.2016

Publisher

Univerzity of Žilina

Location

Žilina, Slovensko

ISSN

1335-0803

Volume

23

Number

1

Pages from–to

33–42

Pages count

10

BIBTEX


@article{BUT126187,
  author="Libor {Válka} and Ivo {Dlouhý},
  title="Fracture behaviour of weld joints made of pearlitic and bainitic steel",
  year="2016",
  volume="23",
  number="1",
  month="June",
  pages="33--42",
  publisher="Univerzity of Žilina",
  address="Žilina, Slovensko",
  issn="1335-0803"
}