Mechanism of the silicon influence on absolute chilling tendency and chill of cast iron

作者：Fras Edward^*; Gorny Marcin; Lopez Hugo F

来源：ISIJ International, 2008, 48(2): 175-179.

DOI：10.2355/isijinternational.48.175

• cast iron
• chilling tendency
• chill

In this work an analytical solution of general validity is used to explain mechanism of the silicon influence on the absolute chill tendency (CT) and chill W of cast iron. It is found that CT an be related to nucleation potential of graphite (N-v), growth parameter (mu) of eutectic cells, temperature range (AT,,,), where Delta T-sc= T-s- T-c (T-s is graphite eutectic equilibrium temperature and Tc is cementite eutectic formation temperature) and the pre-eutectic austenite volume fraction If.). It has been shown that silicon additions: 1) impede the growth of graphite eutectic cells through decreasing graphite eutectic growth coefficient p, 2) expands the temperature range Delta T-sc, 3) increases the nucleation potential of graphite N-v, 4) lowers the pre-eutectic austenite volume fraction, f(gamma) and in consequence the absolute chilling tendency CT decreases. The minimum wall thicknesses for chilled castings, or chill widths, w in wedge shaped castings is related to CT and as Si contents increases, the chill widths, w value decreases.

• 出版日期2008