The invention discloses a production process of high-strength and high-
toughness as-cast ductile
cast iron. Raw materials including
pig iron, low-
carbon steel and ductile
cast iron foundry returns are added to a medium-frequency
melting furnace and heated to be molten, an efficient carburant, a
manganese-iron
alloy and a
silicon-iron
alloy are added to the medium-frequency
melting furnace, and the mixture is molten into molten iron; firstly, a spheroidizing
ladle is preheated, a spheroidizing agent is added to one side, close to a furnace body, of a dam of the spheroidizing
ladle, an inoculant is taken and applied to the surface of the spheroidizing agent in a covering manner,
metal nickel and
metal titanium are added to the other side, close to the furnace body, of the dam of the spheroidizing
ladle, the surface of the spheroidizing agent is covered with a
perlite covering agent, part of molten iron is poured into the spheroidizing agent for a reaction, the remaining molten iron is poured into the spheroidizing agent after the reaction is stable, the remaining inoculant is added along with the flow for
inoculation, the mixture is stirred sufficiently, a molten iron deslagging agent is added after slagging off,
slag is rammed,
silicon granules are added, the mixture is covered with the
perlite covering agent after
inoculation of unstable
silicon, and a product is obtained after pouring and
air cooling. The production process has the advantages that the process is simple, reasonable and low in production cost, heat treatment is not required, the product elongation is increased, and the mechanical performance of the product is good.