Cast steel material and manufacturing method for castings of cast steel material

Abstract

The invention provides a cast steel material with high strength, good toughness and low cost. The cast steel material is composed of, in weight percentage, 0.32-0.40% of C, 0.25-0.45% of Si, 0.50-0.80% of Mn, smaller than or equal to 0.035% of P, smaller than or equal to 0.035% of S, 0.02-0.03% of N, 0.020-0.060% of Al, smaller than or equal to 0.10% of Mo, smaller than or equal to 0.05% of V, smaller than or equal to 0.20% of Ni, smaller than or equal to 0.20% of Cu, smaller than or equal to 0.25% of Cr and the balance Fe and inevitable impurities. According to the cast steel material, on the premise of not increasing the wall thickness and the section ratio of engineering vehicle axle housings and suspensions and not increasing the manufacturing cost, the strength and the toughness of the axle housings and suspension supports are improved, and therefore the bearing capacity can be improved; and according to finite element analysis, the thickness of castings of products can be reduced appropriately, the purpose of light weight can be realized, and the manufacturing cost can be lowered.

Description

technical field [0001] The invention relates to the field of vehicle axle housings and balance suspensions, in particular to cast steel materials and casting methods for engineering vehicle axle housings and suspension systems of medium and heavy trucks and loaders. Background technique [0002] Looking at domestic engineering vehicle cast steel axle housing parts, the materials used are generally QT500-7, ZG310-570, ZG270-500, ZG25Mn, ZG40Cr, SCW550 in the Japanese JIS G5102 (1991) standard, etc. For mechanical properties of each material grade, see figure 1 . For the chemical composition of each material grade, see figure 2 . Depend on figure 1 and figure 2 It can be seen that the QT500-7 material is the most brittle and has the highest carbon equivalent, so it cannot be welded; although ZG40Cr has the highest mechanical properties, it needs to add chromium element, and heat treatment normalizing 830-860 ℃ + tempering 520-680 ℃, high material and heat treatment cost...

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Problems solved by technology

Depend on figure 1 and figure 2 It can be seen that the QT500-7 material is the most brittle and has the highest carbon equivalent, so it cannot be welded; although ZG40Cr has the highest mechanical properties, it needs to add chromium element, and heat treatment normalizing 830-860 ° C + tempering 520-680 ° C, the cost of materials and heat treatment is high ; When ZG25Mn and SCW550 cast and smelt molten steel, low-carbon steel is required, and more manganese elements need to be added, the heat treatment temperature is high, the cost of materials and heat treatment is high, but the mechanical properties are average; ZG270-500 and ZG310-570 although the material cost and heat treatment The cost is lower, but there is no advantage in mechanical performance, which is more general

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