Effect of inoculation and nodularisation treatment temperature on recalescence and eutectic undercooling temperature in Spheroidal graphite (SG) cast iron

ABSTRACT

In this study, the effect of inoculant composition and nodularisation treatment temperature on recalescence temperature (TER) and undercooling temperature (TEU) in SG iron has been studied by using thermal analysis. 0·1, 0·2 and 0·3 wt-% of three types of inoculants Ca,Ce,Al–FeSi, Ca,Sr,Al–FeSi and Ca,Ba,Al–FeSi were used as so called stream inoculation. Ca,Ce,Al–FeSi was found to be the most potent one in reducing both recalescence (∆T _r ) and eutectic undercooling (∆T). The nodule count has also been found higher in Ca,Ce,Al–FeSi inoculated SG iron samples compared to other two inoculants. It has been observed that higher the nodule count lower is the ∆T _r and ∆T and vice versa. The recalescence and shrinkage relationship of 24 heats of differential case castings has been established; it was observed that the number of castings containing shrinkage in respective heats increase as the recalescence and nodularisation treatment temperature increases.

KEYWORDS:

• Inoculation
• undercooling
• recalescence
• nodule count
• thermal analysis
• nodularisation temperature

Abbreviations:

• SG: Spheroidal Graphite
• TER: Temperature of Eutectic Recalescence
• TEU: Temperature of Eutectic Undercooling
• ∆T _r : Recalescence
• ∆T: Eutectic undercooling
• CC: Cooling Curve
• TA: Thermal analysis
• CE: Carbon equivalent
• Ultraseed: Ca, Ce, Al-FeSi
• InoK-S75: Ca, Sr, Al-FeSi
• InoK-SB2: Ca, Ba, Al-FeSi

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Corrigendum

Acknowledgement

Authors gratefully acknowledge OCL Iron and Steel Ltd. (Amtek India) located in Bhiwadi Rajasthan India for permitting to conduct the melting/inoculation trials and assistance in carrying out the thermal analysis.