Ductile Cast Iron Microstructure Adjustment by Means of Heat Treatment

• Autorzy: Mróz M. , Orłowicz A. W. , Tupaj M. , Kupiec B. , Kawiński M.

Identyfikatory

DOI

10.24425/afe.2020.133327

• Języki publikacji: EN

Abstrakty

EN

The study presented in this paper concerned the possibility to apply a heat treatment process to ductile cast-iron thin-walled castings in order to remove excessive quantities of pearlite and eutectic cementite precipitates and thus meet the customer’s requirements. After determining the rates of heating a casting up to and cooling down from 900°C feasible in the used production heat treatment furnace (v_h = 300°C/h and v_c = 200°C/h, respectively), dilatometric tests were carried out to evaluate temperatures T_gr, TAc₁ ^start, TAc₁ <sup/end</end>, TAr₁ ^start, and TAr₁ ^end. The newly acquired knowledge was the base on which conditions for a single-step ferritizing heat treatment securing disintegration of pearlite were developed as well as those of a two-step ferritization process guaranteeing complete disintegration of cementite and arriving at the required ferrite and pearlite content. A purely ferritic matrix and hardness of 119 HB was secured by the treatment scheme: 920°C for 2 hours / v_c = 60°C/h / 720°C for 4 hours. A matrix containing 20–45% of pearlite and hardness of 180–182 HB was obtained by applying: 920°C for 2 hours or 4 hours / v_c = 200°C/h to 650°C / ambient air.

Słowa kluczowe

EN

ductile cast iron; heat treatment; microstructure

PL

żeliwo sferoidalne; obróbka cieplna; mikrostruktura

• Wydawca: Komisja Odlewnictwa Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2020
• Tom: Vol. 20, iss. 3
• Strony: 37--40
• Opis fizyczny: Bibliogr. 6 poz., rys., wykr.

Twórcy

autor

Mróz M.

• Rzeszow University of Technology, Rzeszów, Poland

autor

Orłowicz A. W.

• Rzeszow University of Technology, Rzeszów, Poland

autor

Tupaj M.

• Rzeszow University of Technology, Rzeszów, Poland

autor

Kupiec B.

• Rzeszow University of Technology, Rzeszów, Poland

autor

Kawiński M.

• Cast Iron Foundry KAWMET, Orły, Poland

Bibliografia

• [1] Verdu, C., Hdrien, J. & Reynaud, A. (2005). Amélioration des propriétés de fatigue de fontes GS par traitments thermiques de type Dual Phase. Hommes&Fonderie. 352, 30-33.
• [2] Monchoux, J.P., Verdu, C. & Fougeres, (2000). Effect of a ferritization heat treatment on the fracture toughness of ferritic spheroidal graphite cast iron. Scripta Materialia. 42, 1047-1052.
• [3] Iacoviello, F. & Cocco, V.D. (2016). Influence of the graphite elements morphology on the fatigue crack propagation mechanisms in a ferritic ductile cast iron. Engineering Fracture Mechanics.167, 248-528.
• [4] Iacoviello, F., Cocco, V.D. & Bellili, C. (2019). Overloaded effect on fatigue cracks in a ferritized ductile cast iron. International Journal of Fatigue.127, 376-381.
• [5] Shirani, M. & Härkegård, G. (2011). Large scale axial fatigue of ductile cast iron for heavy section wind tube components. Engineering Failure Analysis. 18,6, 1496-1510. DOI: 10.1016/j.engfailanal.2011.05.005.
• [6] Giacopini, A., Boeri, R.E. & Sikora, J.A. (2003). Carbide dissolution in thin wall ductile iron. Materials Science and Technology. 19, 1755-1760.

Uwagi

PL

Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2020)