High-toughness synthetic cast iron cylinder-sleeve material and manufacturing process

Abstract

The invention discloses a manufacturing process of a high-toughness synthetic cast iron cylinder-sleeve material. The method comprises the following steps: using low-carbon steel scrap as a raw material, carrying out recarburization by adding a carburant, adding ferroalloy and fusing to obtain high-carbon high-silicon molten iron; adding a high-silicon silicon steel sheet into the surface of the molten iron to carry out silicon-increasing and carbon-reduction processing; and adding an instantaneous inoculant into the molten iron to carry out secondary instantaneous compound inoculation treatment, and pouring a blank to prepare the high-toughness synthetic cast iron cylinder-sleeve material. Casting costs of the high-toughness synthetic cast iron provided by the invention are 15-20% lower than casting costs of general alloy cast iron. Tensile strength of the prepared high-toughness synthetic cast iron cylinder-sleeve is 80-130MPa higher than tensile strength of an alloy cast iron cylinder-sleeve, and the tensile strength of the prepared high-toughness synthetic cast iron cylinder-sleeve can reach 350-420 MPa. Hardness can be controlled to 190-240, and hardness difference of the high-toughness synthetic cast iron cylinder-sleeve is shortened by 20HB in comparison with hardness difference of the alloy cast iron cylinder-sleeve and can shortened to delta HB being less than or equal to 10. Elasticity modulus E is greater than or equal to 140GPA. High-toughness synthetic cast iron can be used to reduce wall thickness of the cylinder sleeve and raise power of an engine. In addition, the elasticity modulus is high, hardness is low and processability is good, clearance between a piston and a cylinder can be decreased; noise can be reduced; and power can be increased.

Description

technical field [0001] The invention belongs to the field of preparation of cylinder liner materials, and in particular relates to a high-strength and tough synthetic cast iron cylinder liner material and a manufacturing process thereof. Background technique [0002] High-strength and tough synthetic cast iron has the advantages of fine grain, high elongation, good wear resistance and heat resistance. It is a kind of alloy cast iron that can replace alloy cast iron to manufacture automobile air compressors, engineering machinery cylinder liners, cylinder blocks, and iron-based pistons. It is an ideal material for rings, etc., and is widely used in the production of automobiles and machinery industries. However, because high-strength and tough synthetic cast iron is added with scrap steel during the furnace casting process, it is easy to produce white spots, the casting process is complicated, and its performance is unstable, which limits its application in mechanical industr...

AI Technical Summary

Problems solved by technology

The project needs to add a large amount of copper, nickel, and molybdenum precious alloy materials, the casting cost is high, the hardness is high, and the tensile strength is only increased by 20 MPa

In 2010, "High Strength Synthetic Gray Cast Iron Microstructure, Properties and Fracture Characteristics" by Lin Hao of Xi'an University proposed the influence of different steel scrap additions on the tensile properties and fracture mechanism. The highest tensile strength reached HT300 materials, but did not propose specific product applications and Casting process

There is almost no research on the classification of scrap steel, the main raw material for synthetic cast iron, and the inoculation process is relatively complicated, which often fails to achieve the expected purpose

However, other processes either have insignificant effects, or have complex technical conditions and high costs, and are not suitable for large-scale industrial production.

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