Ultrafine crystal grain semi-trailer axle tube material and processing method of axle tube

Abstract

The invention discloses an ultrafine crystal grain semi-trailer axle tube material and a processing method of an axle tube. The ultrafine crystal grain semi-trailer axle tube comprises the chemical components by weight percent: 0.23-0.28% of C, 0.15-0.30% of Si, 1.30-1.45% of Mn, less than or equal to 0.03% of P, less than or equal to 0.035% of S, less than or equal to 0.01% of Al, less than or equal to 0.25% of Cu, less than or equal to 0.25% of Ni, less than or equal to 0.25% of Cr, less than or equal to 0.15% of Mo and balance Fe and impurities. By adopting residual heat outer wall atomization and residual heat inner wall tempering technique, the invention guarantees the surface hardness of a steel tube, ensures crystal grains to be ultrafine and the impact toughness to be more superior, greatly improves the strength, guarantees the anti-fatigue property of the ultrafine crystal grain semi-trailer axle tube, greatly prolongs the service life and increases the safety factor.

Description

technical field [0001] The invention relates to the processing field of steel pipes, in particular to an ultrafine grain semi-trailer axle tube material and a processing method for the axle tube. Background technique [0002] With the rapid development of my country's economy, heavy-duty vehicles and logistics industries have developed rapidly. In just six or seven years, the output of heavy-duty vehicles has increased by more than ten times, and now the annual output exceeds 400,000 vehicles. Containers, loading and unloading bridges and semi-trailers, etc., thus creating an increasingly strong demand for steel materials. The rear axles of container semi-trailers used to be produced by a three-stage process, that is, about 25mm thick steel plates were bent into square tubes and then welded, and the axle heads were welded at both ends. The process was complicated and the quality of the welds was difficult to guarantee. The traditional hot-rolled steel pipe directly enters th...

AI Technical Summary

Problems solved by technology

The rear axle of the container semi-trailer used to be produced by a three-stage process, that is, a thick steel plate of about 25 mm is bent into a square tube and then welded, and the axle head is welded at both ends. The process is complicated and the quality of the weld is difficult to guarantee.

The traditional hot-rolled steel pipe directly enters the cooling bed for cooling after sizing, the strength of the steel pipe is not high, the surface hardness is not enough, the impact toughness is poor, and the fatigue resistance cannot meet the requirements

In the traditional quenching and tempering process, the method of external spraying and internal spraying is adopted. After water quenching and tempering, the strength of the steel pipe can be improved and the surface hardness can be guaranteed. However, the steel pipe grain is coarse, the service life is greatly reduced, and the production cost is greatly increased.