Diagrams of supercooled austenite transformations of low-carbon and medium-carbon TRIP-steels

• Autorzy: Grajcar A. , Opiela M.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The aim of the paper is to determine the influence of cooling conditions on a structure and a shape of CCT-diagrams of TRIP-aided steels. Design/methodology/approach: The diagrams of undeformed supercooled austenite transformations for low-carbon and medium-carbon steels were determined. The specimens were austenitized at a temperature of 1100°C and cooled from a temperature of 900°C with a rate in a range from 1 to 300°Cs-1. The dilatometric tests were carried out by the use of the DIL805A/D dilatometer with a LVDT-type measuring head. Findings: It was found that obtained CCT-diagrams of low-carbon and medium-carbon steels are favourable for manufacturing TRIP-type steels with multiphase structures. The steels are characterized by large ferritic and bainitic fields and a right-displaced pearlitic range. However, a ferrite fraction obtained after cooling with an optimum rate from a temperature of 900°C is low. Increasing the fraction of the α phase requires two-stage cooling after austenitizing. Research limitations/implications: To obtain the optimum ferrite fraction, it is necessary to modify a cooling course in a range of γ→α transformation. It should result in an effective utilization of the time for the transformation of austenite into the fine-grained ferrite. Practical implications: The obtained diagrams of supercooled austenite transformations can be useful in a determination of a cooling course from a finishing rolling temperature for sheets with a multiphase structure. Originality/value: The diagrams of the undeformed supercooled austenite for the low-carbon and medium-carbon steels containing Nb and Ti microadditions were obtained.

Słowa kluczowe

EN

metallic alloys; TRIP steel; CCT diagram; supercooled austenite

PL

stopy metaliczne; stal TRIP; wykres CTPc; austenit przechłodzony

• Wydawca: International OCSCO World Press
• Czasopismo: Archives of Materials Science and Engineering
• Rocznik: 2008
• Tom: Vol. 32, nr 1
• Strony: 13--16
• Opis fizyczny: Bibliogr. 16 poz.

Twórcy

autor

Grajcar A.

autor

Opiela M.

• Division of Constructional and Special Materials, Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, 44-100 Gliwice, Poland,

Bibliografia

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