Improvement measures for casting process deformation defects of bed castings

1) In view of the insufficient stiffness of the bottom plate, a stiffener is added at the bottom of the model to make the ground surface have enough support points to ensure that the deformation of the bottom plate is less than 2.0mm in the modeling process.

2) For the low grade of casting material, 0.5% Cr was added during batching, and other chemical components were strictly controlled within the required range to ensure the casting material. At the same time, the hardness of the improved casting was tested. It was found that the hardness of the improved casting was generally 190 ~ 220hbw, which met the requirements of customers.

3) The gating system is improved and adopted at the bottom of the two tracks φ 30mm ceramic pipe is used as gate, and three 50 / 60mm ceramic pipes are set on one side of the casting × 9mm inner gate to solve the problem of uneven gate distribution. The improved gating system is shown in the figure.

From January to June 2021, our company adopted new process to produce a total of 135 castings, 4 of which were rejected, and the rejection rate was 2.96%. Statistical results of main waste products. By comparing the scrap rate before and after process improvement, it can be found that the deformation problem has been completely solved.