Optimization And Analysis Of Heat Treatment Of QT500-7 Forklift Drive Axle Housing

As an exclusive important material handling machine,the forklift is playing a great role in economic development,especially in this rapid developing age.The forklift is so popular in material handling market for its great efficiency and flexibility.It is reported that the sales volume in Chinese market reached 300,000 in 2014,which means the forklift has been an indispensible part of industry production.Driving system and lifting system are always treated as the most important parts of the forklift,so the driving axle which works as the connection of these two systems is crucial for the machine.Normally,the driving axle has to take the horizontal force from the traction system and vertical force from the self-weight of mast as well as cargo,so the material selection and thermal treatment of the driving axle housing are great important.This article presents the following three research results:1?The material selection of the driving axle housingGrey cast iron,nodular cast iron,cast steel are widely used.As concern of mechanical property,metallurgical structure and processing property,the QT500-7 is recommended.2?The Thermal treatment of the driving axleAs regard to the common thermal treatment methods of nodular cast iron,normalization,annealing,quenching and tempering.Normalization is preferred as its simple process and good performance and stage I Normalization is recommended because it requires no special controlling process.3?Mechanical property test and metallurgical structure analysis were taken on the specimens after thermal treatment.The result shows the normalization treatment could provide both better tensile strength and better elongation,so it is selected.