After testing the material, metallography and hardness of 31 kinds of parts, 4 of them have spheroidization grade which does not meet the requirements. Through communication with the physical and chemical room and technology, it is suggested that the purchasing department organize the supplier to improve. In the later stage of testing, it is suggested that the purchasing department inform the supplier to provide tensile strength and tensile test bar at the same time, so as to facilitate the final evaluation of products