Gray cast iron with different carbon equivalent Ce (3.2%, 3.4%, 3.6%, 3.8%, calculated by ce=si/3+ct, Si is taken as the mass percentage, CT is the actual carbon content) used in the test is prepared in the medium frequency induction furnace by metal mold (as shown in the figure), and its composition is shown in the table. First, pig iron and scrap are melted and added with master alloys (Cu, Mo, Sn). The temperature of molten iron is controlled at 1500 ℃, and it is left for 10 min. 1480 ℃ is transferred to ladle inoculation (2/3 ladle bottom flushing method, and the rest is inoculated with the furnace). Gray cast iron samples are cast at 1450 ℃.
The microstructure was analyzed by leica-dm2700m optical microscope and quanta400f scanning electron microscope; Hb-3000 Brinell hardness tester is used for hardness test; The tensile properties were tested by ddl300 electronic universal testing machine with a tensile rate of 1mm/min; The thermal conductivity was measured on TA instruments:dlf1200 laser flash thermal conductivity meter by using the flash method.