Effect of Hydrostatic Extrusion with Back Pressure on Mechanical Properties of Grey and Nodular Cast Irons

Open access

Effect of Hydrostatic Extrusion with Back Pressure on Mechanical Properties of Grey and Nodular Cast Irons

Cold hydrostatic extrusion with and without back pressure of ferritic-pearlitic grey cast iron EN-GJL 250 and ferritic-pearlitic nodular cast iron EN-GJS 500-7 has been performed. The experiments were performed on a originally designed hydrostatic extrusion press operating up to 2000 MPa with back pressure up to 700 MPa. Cast irons were cold hydrostatically extruded with back pressure in one pass with extrusion ratios up to 1.77 and 2.12 for grey and nodular one, respectively. Nodular cast iron was also successfully extruded without back pressure with extrusion ratio 1.35. Severe plastic deformation has led to axial alignment and elongation of graphite inclusions in extrusion direction together with sound flow of the surrounding metal matrix accommodating the strain without cracking. External high pressure has restrained of cracks generation and propagation during the material flow and healed of already existing defects by internal friction caused by plastic flow. It was visualized by aligned and elongated graphite flakes and nodules and no cracks and porosity observed in surrounded metal matrix. Very high compressive strength of both materials has been measured, above 1000 MPa and ~2400 MPa for grey and nodular cast iron, respectively. These values were accompanied by above 3000 MPa and above 3400 MPa microhardnes HV0.2 and by over 15% and over 50% elongation at maximum strength for those materials, respectively. Cast irons with such properties can be classified as a new iron-base structural materials.

L. Haenny, G. Zambelli, The stiffness and modulus of elasticity of grey cast irons, J Mater Sci Lett 2, 239-242 (1983).

M. Ramadan, M. Takita, H. Nomura, Effect of semi-solid processing on solidification microstructure and mechanical properties of gray cast iron, Mater Sci Engin A 417, 166-173 (2006).

W. Wei, J. Tianfu, G. Yuwei, Q. Guiying, Z. Xin, Properties of gray cast iron with oriented graphite flakes, J Mater Proces Technol 182, 593-597 (2007).

K. Qi, F. Yu, F. Bai, Z. Yan, Z. Wang, T. Li, Research on the hot deformation behaviour and graphite morphology of spheroidal graphite cast iron at high strain rate, Materials and Design 30, 4511-4515 (2009).

N. P. Lyakishev, G. V. Shcherbedinskii, Hot plastic deformation of high-strength cast iron, Metal Science and Heat Treatment 43, 421-422 (2001).

V. Shumikhin, Deformed ductile cast-iron. Science and Innovation, special issue 2007; p.104, www.atsukr.org.ua. www.atsukr.org.ua

J. Baca, A. S. Chaus, Effect of plastic deformation on the structure and properties of cast iron with globular graphite, Metal Science and Heat Treatment 46, 188-191 (2004).

H. Ll.D. Pugh, A. H. Low, J. Inst Metals 93, 201 (1964).

D. K. Bulychev, B. I. Beresnev, Fiz. Metal. Metalloved 13, 942 (1962).

H. Ll.D. Pugh, The application of hydrostatic pressure to the forming of metals. In: H. Ll.D. Pugh, editor. Mechanical behaviour of materials under pressure, Amsterdam: Elsevier Publ Co Ltd; p.522-590 (1970).

H. Ll.D. Pugh, D. Green, Progress Report on the behaviour of materials under hydrostatic pressure, MERL Plasticity Report No 147, National Engineering Laboratory, East Kilbride, Glasgow (1958).

H. Ll.D. Pugh, D. Gunn, Symposium on the physics and chemistry of high pressures, Society of Chemical Industry, London, p.157-162 (1963).

B. Avitzur, Handbook of Metal-forming Processes. New York: John Wiley & Sons Inc; p.103 (1983).

M. J. Dong, C. Prioul, D. Francois, Damage effect on the fracture toughness of nodular cast iron: Part I. Damage characterization and plastic flow stress modelling, Metall Mater Tran A, 28A, 2245-2254 (1997).

T. Seifert, H. Riedel, Mechanism-based thermomechanical fatique life prediction of cast iron. Part I: Models, Int J Fatique 32, 1358-1367 (2010).

G. V. Shcherbedinskii, Iron: promising material of the XXI century, Metal Science and Heat Treatment 47, 333-342 (2005).

Archives of Metallurgy and Materials

The Journal of Institute of Metallurgy and Materials Science and Commitee on Metallurgy of Polish Academy of Sciences

Journal Information


IMPACT FACTOR 2016: 0.571
5-year IMPACT FACTOR: 0.776

CiteScore 2016: 0.85

SCImago Journal Rank (SJR) 2016: 0.347
Source Normalized Impact per Paper (SNIP) 2016: 0.740

Cited By

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 168 149 11
PDF Downloads 78 74 5