Effects of K2CO3 Addition on Inclusions in High-Carbon Steel for Saw Wire

In order to avoid the formation of crack initiation sites, inclusions in high-carbon steel for saw wire are strictly required to have excellent deformability. However, it is hard to achieve this goal with only conventional inclusion softening art, such as Si-Mn deoxidation and low basicity top slag refining. Therefore, a new method should be put forward to enhance the deformability of inclusions. Low melting temperature inclusions are widely considered to have good deformability, hence, adding K (potassium) into inclusions may become a potential new method to better enhance the deformability of inclusions due to the pronounced effect of K2O on lowering the melting temperature of inclusions. In the present study, the influences of Fe/K2CO3 (weight ratio), K2CO3 addition amount and reaction time on inclusions were investigated by using a graphite tube resistance furnace. Through this study, a solution to adding K into inclusions effectively by K2CO3 addition was developed and the melting temperature of inclusions was significantly reduced. In addition, the reaction mechanism between K2CO3/slag/steel/inclusion was deduced and the relation between deformability and crystallinity of inclusions was also briefly discussed.