Spheroidal graphite cast iron cast gear and machining process thereof

Abstract

The invention discloses a spherodial graphite cast iron cast gear and a machining process thereof. The spherodial graphite cast iron cast gear mainly comprises, by weight, 3.5%-3.6% of C, 2.3%-2.4% of Si, 0.4%-0.45% of Mn, less than 0.1% of Cr, 0.4%-0.45% of Cu, 0.03%-0.045% of Mg, not larger than 0.02% of S, not larger than 0.05% of P and the balance Fe. The machining process of the gear includes the following steps of firstly, molten iron smelting, secondly, spheroidizing inoculation, thirdly, casting molding, fourthly, shot blasting, fifthly, thermal treatment, sixthly, rough machining, seventhly, surface hardening and eighthly, finish machining. According to the cast gear, low-manganese scrap steel serves as a raw material, production cost can be lowered, and the gear cast through spherodial graphite cast iron has the comprehensive performances of being high in strength, high in wear resistance and high in flexibility and can meet the requirement of a transmission gear.

Description

technical field [0001] The invention belongs to the field of processing gears of gearboxes for passenger vehicles, and in particular relates to a casting gear made of ductile iron and a processing technology thereof. Background technique [0002] Gearbox gears are important transmission components, requiring high strength, good toughness and surface wear resistance. However, traditional gear production is forged from gear steel (including low-carbon steel, low-carbon alloy steel, medium-carbon steel, and medium-carbon alloy steel), and forming steel must be used, with strict composition requirements and relatively high prices. Moreover, forging production efficiency is low, generally no more than 500 pieces per hour; forgings need to consume more energy during blanking and forging processes, which increases production costs and causes energy waste; forged gear blanks have poor dimensional accuracy and processing If the margin is large and the control is not good, it is easy...

AI Technical Summary

Problems solved by technology

However, traditional gear production is forged from gear steel (including low-carbon steel, low-carbon alloy steel, medium-carbon steel, and medium-carbon alloy steel), and forming steel must be used, with strict composition requirements and relatively high prices

Moreover, forging production efficiency is low, generally no more than 500 pieces per hour; forgings need to consume more energy during blanking and forging processes, which increases production costs and causes energy waste; forged gear blanks have poor dimensional accuracy and processing If the margin is large and the control is not good, it is easy to appear banded structure, which is not good for the performance of the product