Abrasion-Resistant White Cast Iron-ASTM A532_A532M
- 5.3 Rational selection of matrix structure of high chromium white cast iron continued.
The results of the wear surface analysis show that in martensite + bainite + austenite matrix. Maybe the impact fatigue exfoliation is obviously smaller than martensite matrix. Furthermore the microcrack is smaller than martensite. Which is related to the distribution of martensite + bainite + austenite basic tissue. It seems like it is easy to produce the crack initiation of carbide.
Surrounded by bainite austenite is surrounded by bainite. And martensite is located in the region of austenite transformation away from bainite. Even if the carbide microcracks occur in the impact abrasive wear. The surrounding matrix is bainite and austenite with a certain impact resistance. And the austenite has a good passivation on the crack. As a result which makes the crack difficult to expand. In conclusion it does not crack quickly like martensite to form a net and accelerates the fatigue exfoliation of the matrix.
The results of the study and the field contrast test show that the martensitic matrix shows good abrasion resistance in low stress abrasive wear. While martensitic + bainite + austenite structure shows good abrasion resistance and impact fatigue resistance in high stress and impact load abrasive wear.
