Effect of tin on microstructure and mechanical properties of compacted graphite iron

Abstract

This experiment investigated the effect of tin in an amount up to 0?121 wt-% on the microstructure and mechanical properties of compacted graphite iron. Graphite and matrix evolution was emphasised with the help of scanning electron microscopy. The results indicate that Sn in experimental range reduces graphite size. Pearlite quantity would increase with the increasing Sn and reaches over 95% when Sn is .0?057 wt-%. Sn helps to narrow the lamellar spacing of pearlite from sorbitic pearlite (320 nm) to troostitic pearlite (83 nm) when Sn increases from 0?003 to 0?057 wt-%. Appropriate Sn addition promotes the tensile strength and impact toughness, and the samples containing 0?057 wt-%Sn perform the highest values of 410?7 MPa and 9?11 J cm 22 respectively. Elongation declines with increasing Sn content because of the emergence of more pearlite. Samples containing excessive Sn experience sharp deterioration in mechanical properties due to brittle cementite. Y. Lyu et al. Effect of tin on properties of CGI International Journal of Cast Metals Research 2015 VOL NO 3 28 5 265 Downloaded by [University of Sussex Library] at 04:48 22 June 2016 4 Energy dispersive spectroscopy analysis of massive phase in sample containing 0.121 wt-%Sn 6 Lamellar spacing of samples containing a 0.003 wt-%Sn and b 0.057 wt-%Sn 5 Energy dispersive spectroscopy analysis of samples containing 0.092 wt-%Sn Y. Lyu et al. Effect of tin on properties of CGI

Extrema of micro-hardness in fully pearlitic compacted graphite cast iron

“…This would lead to an increase in the interlamellar spacing for given casting conditions and cooling rate and thus to a decrease in micro-hardness close to graphite precipitates. Note that this explana tion would apply to fully pearlitic matrix and not to cast irons containing some ferrite located around graphite precipitates as in the recent work by Liu et al [21]. This suggestion would be worth dedicated experiments involving isothermal growth of pearlite after austenitization.…”

Abrasive Wear of Compacted Graphite Cast Iron with Added Tin

“…Usually, during eutectic reaction, carbon atoms continuously move from austenite to graphite and leave a C-lack area around graphite, which will finally become ferrite. Lyu et al [19] demonstrated that Sn tends to exist at the boundary between graphite and austenite during eutectic reaction, obstructing the C transfer. Consequently, the areas close to vermicular graphite contained enough C atoms to form pearlite.…”

“…On the other hand, alloying is likely to be an easy way to improve the properties of CGI. Copper, titanium, and tin were found to be effective in increasing the strength of CGI by promoting the formation of pearlite [17][18][19], but the influences of these alloys to the wear resistance of CGI is not fully understood.…”

An Investigation of Effect of Tin (Sn) on Microstructures and Mechanical Properties of Gray Cast Iron

“…Shaban et al showed that tin (Sn) increased compact graphite and graphite aspect ratio [9]. In their study in vermicular cast iron, Lyu et al found out that graphite size clearly decreased as tin (Sn) content increased between 0.003 and 0.057% by weight and an increase in tensile strength and impact toughness was obtained [10]. In a study on nodular cast iron by Lacaze et al, it's determined that tin rate was harmful after 0.05% [11].…”