The bimetallic jaw wear-resistant castings were successfully wound by using the bimetallic liquid winding injection / transformation molding technology of wear-resistant castings. The composite casting method includes two process steps of “changing the upper mold” and “bimetallic liquid sparing injection”. The process adopts the winding injection mode of high chromium cast iron and then low carbon steel, and the two metals are injected into the mold before and after the transformation respectively (as shown in the figure).
The analysis of bimetallic microstructure by Guan Ping shows that the cast iron layer is mainly composed of tempered martensite and retained austenite; The carbon steel layer is a typical eutectoid steel structure (ferrite and pearlite). The thickness of the transition zone is about, and its composition also presents transition characteristics. The interface structure is uniform, dense and less defects. There is metallurgical bonding between the two layers of metal, and the initial impact resistance of the sample material is greatly improved.
The bimetallic liquid pouring / transformation molding process does not need quantitative packing, and the on-site operation is fast. The cast iron wear-resistant layer of the particle plate can be directly injected; Before transformation, the metal upper mold has good heat dissipation performance, which is conducive to the rapid cooling of the first wound high chromium cast iron and can refine the grain; The combination can be controlled to any curved surface through NC machining. The wavy interface of jaw plate in the figure above increases the bonding area between bimetals, which is firm and reliable, and can adapt to the production of bimetallic wear-resistant castings with arc curved surface and uneven interface thickness.