The results show that the laser surface biomimetic strengthening technology can effectively improve the fatigue wear resistance of gray cast iron. This is because martensite, austenite and other strengthening phases appear in the laser processing area, and a large number of carbides (cementite) further strengthen the unit body area, so as to improve the fatigue wear resistance of gray cast iron. Therefore, the content of carbides will obviously directly affect the fatigue wear resistance of gray cast iron. However, due to the influence of alloying element content of gray cast iron, the improvement of fatigue wear resistance of gray cast iron by laser treatment is seriously restricted. Therefore, in this chapter, by means of laser alloying, a large number of alloy elements are introduced into the melting zone to participate in the reaction in the melting process, so that the processing area can be further strengthened.

Laser alloying technology can well introduce the required alloy elements into the strengthening area, and the content of alloy elements can be freely controlled. Moreover, according to the service conditions of gray cast iron, the type of single alloy element or the mixture of multiple alloy elements can be freely selected. W- and cr- are commonly used wear-resistant reinforced gray cast iron materials, in which Cr3C2, Cr7C3, WC, w7c3, W3C and other strengthening phases will be formed. Traditionally, carbides or oxides formed by W or Cr are adsorbed on the surface of gray cast iron by coating to form a layer of strengthening film. This method can effectively improve the surface properties of gray cast iron. However, due to the combination form of coating and matrix, this method is not suitable for improving the rolling fatigue wear properties of gray cast iron. Therefore, the research content is to compare the effect of W or Cr or w+cr on the fatigue wear resistance of gray cast iron under the action of laser alloying.