In the iron casting , the content of carbon and silicon is low and nearly all of the carbon form the cementite with iron . It is called white cast iron because of the argenteous fracture of it . The crystalline grain of the fracture is coarse and the fracture has apparent directional . It is a kind of good antifriction material.
White cast iron include plain white cast iron , low alloy white cast iron , medium alloy white cast iron and high alloy white cast iron.
Plain white cast iron : have no alloy elements . In engineering , it is applied to produce resist-wear casts that abrasion performance is not high.
Low alloy white cast iron : the wear resistance will be increased if plain white cast iron is added a small amount of alloy elements . However , this kind of iron casting still has a biggish brittleness.
Medium alloy white cast iron : including Ni-cast iron , Mn white cast iron , Mn-W white cast iron , W-Cr white cast iron and medium Cr white cast iron .
High alloy white cast iron : high Cr white cast iron is the most widely used in it , and de content of Cr is from 12%~20%.