Motorcycle handlebar tube rupture Issues

 

    State-owned machinery plant Zheng Jie Jialing

 

    CJoo motorcycle handlebar pipe material grades for the finishing B8F made of welded steel. Since handlebar large deformation, to go through two curved, so the higher toughness, but also requires a good weld properties. In the production process, found in the curved handle tube rupture occurs when, after inspection of the pipe rupture, found fault mostly from the weld start to prove the birthplace of the weld is broken.

 

    Heat pipe rupture of the opponents.

 

    After Rolled steel for metallographic analysis elongated grain, the grain restitution to be recrystallization annealed. If the annealing temperature is selected properly, the performance of the steel has a great influence. BsF category are carbon steel, fire temperature is too low, can not completely eliminate the residual stress and deformation of the grain can not restitution, the annealing temperature is too high, the grain will become thick, the brittleness of the steel increases, so In curved prone to fracture.

 

    Carbon content effect on weldability.

 

    Managers of the analysis showed that the carbon content of the handle pipe 0.26qo, the maximum carbon content of more than BsF 0.02%. Due to the melting in the welding heat affected zone to a temperature far exceeds the critical point of steel, about 1200 ℃ degrees Moreover, since the concentration of the heat source. The welding conditions in complex organizational changes carried out under stress, various parts of the maximum heating temperature difference will cause differences in organizational change and the whole joint tissue heterogeneity. At the end of welding, heat affected zone and is not heated by the surrounding body parts tomb chilling, the heat affected zone caused great cold, resulting in a lot of heat stress and stress, and sometimes even occur Markov changes in the body, the equivalent being quenched. The heat affected zone cracking tendency major decisions I hardenability of steel and hardenability, both major and determined carbon content of steel. Because of the hardness of steel after quenching and organizations related to the amount of martensite, while the amount of martensite and the carbon content in steel related. The higher the carbon content of the steel is greater weld cracking tendency.

 

    For the handlebar of the pipe material, the carbon content of 0.26%, higher than normal material, is caused by the high hardness of the weld zone causes, so that when subjected to large deformation processing is easy to break, the analysis type is caused by CJio motorcycle handlebar tube curved rupture of the main factors.

 

    After analysis and research the following conclusions can be drawn.

 

    In order to improve the utilization of welded steel pipe and product quality, reduce scrap rates, so that pipe can adapt to the needs of large deformation parts should pay attention to the following aspects. .

 

    1. According to choose the ideal processing requirements of steel.

 

    2. Select the appropriate annealing temperature and time.

 

    3. Develop a reasonable welding process, improve the welding quality.