Abrasion-Resistant White Cast Iron 13
2.5 High chromium white cast iron
Since the early 70 s in China carried out the research work of high chromium white cast iron. And also has established a complete series of high chromium abrasion resistant material. Like grinding balls, lining board, composite rolls and more than 100 kinds of wear-resistant castings use the material. And shows good anti-wear performance. In table 4 listed the main composition and properties of high chromium white cast iron commonly used in China.
Table 4 The main composition and properties of high chromium white cast iron commonly used in China
|Material grade||chemical composition %||Hardness HRC|
|C||Cr||Mo||Cu||Ni||Si||Cast state||quenched state||softening state|
|KmTBCr15Mo2- DT||2.0-2.8||13-18||0.5-2.5||0-1.2||0-1.0||≤ 1.0||40-56||≧58||≤ 40|
|KmTBCr15Mo2 – GT||2.8-3.5||13-18||0.5-3.0||0-1.2||0-1.0||≤ 1.0||50-58||≧58||≤ 40|
|KmTBCr20Mo2Cu||2.0-3.0||18-22||1.5-2.5||0.8-1.2||0-1.5||≤ 1.0||50-58||≧58||≤ 40|
|KmTBCr26||2.3-3.0||23-28||0-1.0||0-2.0||0-1.5||≤ 1.0||50-58||≧58||≤ 40|
The research work of high chromium cast iron mainly starts from the 15-3 type, and develops Cr12 and Cr24 type according to the national conditions. In view of the fact that the price of molybdenum is very expensive in China, the engineers developed molybdenum free or low molybdenum and high chromium white cast iron. They are high chromium manganese molybdenum cast iron (3.0% ~ 5.0% Mn, 0 ~ 0.5%Mo), high – manganese tungsten cast iron (2.0% – 4.0% Mn + W), high chromium – manganese aluminum cast iron (3.0% – 5.0%Mn, >016%Al).High chromium cast iron is mainly used in the production of wear parts. Such as grinding ball, liner, impurity pump, bimetal roll, and so on. The status and good effect of high chromium cast iron in the field of abrasive material and wear resistance is being gradually recognized. And it will become the dominant anti-wear material.
2.6 High tungsten white cast iron
High tungsten white cast iron has high anti-wear properties. Especially has Chinese charateristics. Under the condition of the backlog of tungsten and iron at that time. It’s main components are 11% ~ 13%W. And the HRC reaches 60~64,αk10J / cm2 after hardening heat treatment. In recent years due to the rising price of W elements, the production cost is relatively high. The recently developed W Cr white cast iron (5%W, 4%Cr) has further improved the antiwear performance And it has achieved good results for impurity pumps.