A kind of vanadium-titanium gray cast iron and its production process

Abstract

The invention particularly relates to a vanadium-titanium gray cast iron and a production technique thereof. The vanadium-titanium gray cast iron contains 3.2-3.6% of C, 1.6-1.9% of Si, 0.7-0.9% of Mn, 0-0.10% of P, 0.07-0.12% of S, 0.15-0.20% of V, 0.07-0.12% of Ti, 0.25-0.35% of Cr, and the balance of Fe and other minor elements and inevitable impurities. The vanadium-titanium gray cast iron has the advantages of high tensile strength, favorable heat resistance and favorable wear resistance; and the type-A graphite content in the metallurgical structure is higher than 85%, the graphite length is Grade 3-5, the pearlite content in the matrix structure is greater than or equal to 98%, and the total content of carbides and iron phosphide eutectic is less than or equal to 2%.Late inoculation treatment is adopted to enhance the inoculation effect, improve the graphite form, eliminate the carbides and ferrite and increase the pearlite content. By using cheap vanadium-titanium pig iron as the raw material and avoiding adding noble alloys, the vanadium-titanium gray cast iron has the advantages of low cost and high performance.

Description

technical field [0001] The invention relates to the field of casting metal materials, in particular to a vanadium-titanium gray cast iron and a production process thereof. Background technique [0002] Automobile brake drums are important safety parts of automobiles and are used under thermal fatigue and wear conditions. Therefore, it is required that the material for preparing the brake drum must have good thermal fatigue resistance and wear resistance. Automobile brake drums are generally produced with high-strength gray cast iron, and the material development direction is high thermal conductivity and high strength. Generally, the thermal conductivity is improved by increasing the carbon content and the graphite morphology, and the strength is improved by adding alloying elements. The common cast iron brake drum is made of HT250, with a carbon content of 3.2 to 3.5%, adding 0.5 to 0.6% of copper for alloying. [0003] The main problems existing in the use of ordinary c...

AI Technical Summary

Problems solved by technology

However, since Ti is a supercooled element, it is also an element that significantly improves strength. If the Ti content is too high, supercooled graphite will be formed, which will significantly reduce thermal conductivity, thereby reducing thermal fatigue resistance. If the Ti content is too low, it will not be conducive to improving the strength.

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