| 摘要 |
A conventional method of producing cast steel is casting coupling method causing problems such as a pin hole, a blow hole, a crack, and the like. To solve the problems, the present invention comprises: forming an inner bent portion by using a hydraulic machine after a steel plate as a raw material is cut by a press; cutting the edge; trimming the outside; welding a front and a rear side of a body unit; grinding area to be welded; and welding left and right wing sides and upper and lower wing sides in order for a manufacturing process to be completed. |
