1. The grade of carbide segregation does not meet the requirements
Carbide segregation grade mismatch mainly occurs in ledeburite die steel.T he main reason is that the carbide in the forging process by forging press is not evenly distributed.Concentrated distribution or reticulate distribution. The main reason for this defect is the poor grade of carbide segregation,in addition, the forging ratio is not enough or the forging method is not proper when the forging is changed.Forgings with such defects are prone to local overheating and cracking during heat treatment and quenching.Blade and mould are easy to break when used.
Banding structure is a kind of structure in which ferrite and pearlite, ferrite and austenite, ferrite and bainite, ferrite and martensite are distributed in banding in forging.They are mostly found in hypoeutectic, austenitic and semi-martensitic steels.It is often easy to crack along the ferrite belt or the junction of two phases in forging or working parts.
3,Part insufficient fill
Local insufficient filling mainly occurs in rib, convex Angle, corner, round corner, size does not meet the requirements of the drawing. The reasons may be as follows:(1) forging temperature is low, poor metal fluidity; (2) forging press equipment tonnage is not enough or hammer force is insufficient;(3) billet die design is not reasonable, billet volume or section size is not qualified; (4) the mold chamber deposited oxide or welded deformation metal.
Undervoltage refers to the vertical direction of parting die size generally increased, the reason may be: (1) the forging temperature is low. (2) equipment tonnage is insufficient, hammer force is insufficient or hammer times are insufficient.Haloong servo CNC forging press adopts servo motor direct drive, accurate ability control,which is very helpful.
Misalignment is the displacement of the upper part of the die face relative to the lower part.The reason may be: (1) slide block (hammer head) and the clearance between the guide rail is too large; (2) the design of the forging die is not reasonable, the lack of the lock or guide column to eliminate the wrong shifting force; (3) Wrong mold installation.
6. Axis bending
The axis of the forging is bent and there is an error with the geometric position of the plane. The reasons may be as follows:(1) Do not pay attention the forging when out of the die; (2) Cutting edge stress uneven; (3) when the forging cooling parts of the cooling speed is different; (4) cleaning and heat treatment improper.