The present paper deals with the evaluation of the eect of different vacuum heat treatments on the microstructure and fracture surfaces of a low alloyed sintered Fe[1.5Cr0.2Mo]0.6C steel, in correlation with the mechanical and plastic properties achieved. The heat treatment consists of the sintering process in vacuum furnace at 1393 K for 1800 s, followed by different cooling conditions and an integrated final tempering at 473 K for 3600 s. The average cooling rates, calculated in the range of 1393 K to 673 K, were 0.1, 0.235, 3, and 6 K/s, respectively. Vacuum heat treatment is supporting the bainitic-martensitic microstructure, the higher the faster cooling rate applied. This provides a marked increase in strength coupled to a decrease in ductility. The decrease of the impact energy after heat treatment is justied by the microstructural changes, especially if a part of bainite is converted to brittle martensite. Samples with bainitic microstructure presented higher impact energies than those with martensitic microstructure. This is fully confirmed by the fracture surface analysis at higher magnication, revealing three main micromechanisms of fracture: brittle, ductile and quasi-cleavage.

Correlation between Microstructure/Fracture Surfaces and Material Properties / Bidulsky, Robert; Bidulska, J.; ACTIS GRANDE, Marco. - In: ACTA PHYSICA POLONICA A. - ISSN 0587-4246. - STAMPA. - 122:3(2012), pp. 548-552.

Correlation between Microstructure/Fracture Surfaces and Material Properties

BIDULSKY, ROBERT;ACTIS GRANDE, MARCO
2012

Abstract

The present paper deals with the evaluation of the eect of different vacuum heat treatments on the microstructure and fracture surfaces of a low alloyed sintered Fe[1.5Cr0.2Mo]0.6C steel, in correlation with the mechanical and plastic properties achieved. The heat treatment consists of the sintering process in vacuum furnace at 1393 K for 1800 s, followed by different cooling conditions and an integrated final tempering at 473 K for 3600 s. The average cooling rates, calculated in the range of 1393 K to 673 K, were 0.1, 0.235, 3, and 6 K/s, respectively. Vacuum heat treatment is supporting the bainitic-martensitic microstructure, the higher the faster cooling rate applied. This provides a marked increase in strength coupled to a decrease in ductility. The decrease of the impact energy after heat treatment is justied by the microstructural changes, especially if a part of bainite is converted to brittle martensite. Samples with bainitic microstructure presented higher impact energies than those with martensitic microstructure. This is fully confirmed by the fracture surface analysis at higher magnication, revealing three main micromechanisms of fracture: brittle, ductile and quasi-cleavage.
File in questo prodotto:
File Dimensione Formato  
Acta_phys_pol_A_122-2012-548.pdf

non disponibili

Tipologia: 2. Post-print / Author's Accepted Manuscript
Licenza: Non Pubblico - Accesso privato/ristretto
Dimensione 4.19 MB
Formato Adobe PDF
4.19 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2502986
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo