Notice
Advantages of cemented carbide punching dies: high strength, excellent wear resistance
Shortcomings of cemented carbide punching dies: compared to stamping die made of steel, cemented carbide stamping die has lower toughness, brittleness and smaller expansion coefficient.
Precautions for use
1.Requirements for the equipments
The stamping machinery should be in a good working condition when it is used;
The mold bracket should not be damaged;
The end face of female mold and punch should remain parallel;
When adjusting the equipment, the punch should not be used to strike cemented carbide female mold;
Appropriate lubricant should be used for the punching die or extrusion die.
2.Requirements for the parts to be machined
The material surface should be smooth. A material with smooth surface is not easy to be ruptured and damage the mold when stamping forming.
Cemented carbide with good impact toughness, good fatigue resistance, good flexural strength and good abrasion resistance is the ideal material for processing. The grade YG8, YGL5, YG20C, ZL35, ZL40.1, ZL40.2, ZL40.5 and ZL45 are usually selected.
Generally speaking, the improvement of wear resistance will inevitably lead to a decrease in toughness, and in turn the improvement of toughness will inevitably lead to a reduction in the wear resistance. So we should focus on the processing target and processing condition and select the suitable material.
If the selecting grade is easy to be cracked and damaged in the early stage, low hardness and high toughness grade is suitable. If the selecting grade is easy to be damaged in the early stage, grades with high hardness and good wear resistance are better. The following grade: YG8, ZL35, YGL5, ZL40.1 ZL40.2 YG20C ZL40.5, ZL45, from left to right, the hardness and abrasion resistance reduced and the toughness increased.
Precautions for processing cemented carbide punching dies
1.During transportation, we should protect the cemented carbide products from colliding.
2.During grinding, we recommended a resin binder diamond grinding wheel with concentration of 75% for processing; it should also be noted the cemented carbide stamping die should be cooled sufficiently in order to avoid generating machining stress concentration or grinding cracks.
3.Cemented carbide products are not allowed to be compressed.
4.Cemented carbide inserts welded under high temperature should be slow (insulation) cooled slowly.
Reasons for producing waste
1.The set of die blanks and die sleeves is not strong enough.
2.The punching metal will adhere to the wall of the hole due to the poor quality of the polished surface of the die hole.
3.The gap error between female mold and punch will cause fracture in female mold.
4.There are abrupt edges in the carbide concave mold portion. Due to the effect of the deforming force, the angular portion is most likely to rupture in early stage.