U-shaped part machining process and die

The invention relates to a U-shaped part machining process and a die. The die comprises an upper male die, a lower female die and a material supporting seat. The upper male die is fixed to the upper die plate and comprises a male die fixing frame, a first male die insert, a second male die insert and a third male die insert. The lower female die comprises a first lower female die insert, a second lower female die insert, a first female die fixing plate, a second female die fixing plate, a female die fixing backrest block and a lower die base. The material supporting seat comprises a material supporting block upper plate, a lower frame, a die assembly guide column and a positioning pin, 4-degree small-angle inclined material supporting is adopted, 10-degree compensation and 4-degree compensation are adopted on the left side and the right side respectively, meanwhile, compensation is calculated for a fillet arc R100 and a fillet arc R50, and the compensation values are designed to be R81.5 and R38.5 respectivel