Tungsten steel cold extrusion dieis one of the fastener moulds, including processing technology "cold extrusion", is the metal blank in cold extrusion cavity, at room temperature, through the press fixed punch pressing blank to make metal blank parts made by plastic deformation processing approach.

Cold extrusion is at room temperature to plastic deformation of metal material, the unit extrusion pressure is quite big, at the same time due to the turbulent flow of metal materials produced by the thermal effect can make the mould work part temperature as high as 200 ℃ above, plus the severe wear and repeated actions of load, the mould are harsh working conditions.

Therefore, the cold extrusion dies of tungsten steel should have the following characteristics:

1. The mould should have sufficient strength and rigidity to work under the stress of cold and heat.

2. The parts of the mould shall have high strength, high hardness, high wear resistance, and certain toughness;

3. The geometrical shape of convex and concave modes should be reasonable, and the transition should be made to avoid stress concentration by using a large smooth circular arc.

4. Easy to replace the vulnerable parts of the die, and the interchangeability and universality of different extruded parts;

5. In order to improve the strength of the mould work, the concave mode is usually used in the prestressed combination of the concave mould.

In the guide pin, guide sleeve is tungsten steel mold standard parts, guide pin, guide sleeve is the main structure for different diameter of concentric cylindrical surface, the choice of material according to the requirements of the guide pillar structure size and material, directly select the appropriate size of hot rolled round steel as the blank material, after carburizing and quenching, in grinding.

The guide post of thetungsten steel mould is mounted on the mould seat. The guide sleeve is mounted on the upper module. The clearance between the guide column and the guide sleeve is smaller than that of the punch and the die.

The requirements of tungsten steel mould guide material:

Tungsten steel mold guide post heart requires good toughness, generally selects for 20 carbon steel material, blanking length should be considered when turning the clamping length, cylindrical stay 3-4 mm cutting allowance, after turning the external cylindrical grinding allowance should be 0.5 mm, permeable zone depth of 0.8 1.2 mm, surface hardness after quenching for 50 to 55 HRC, outer grinder or universal cylindrical grinding machine grinding, grinding should leave after grinding allowance of 0.01-0.01 mm, for the purpose of grinding process is to further improve the quality of roller surface, in order to eliminate the heat caused by neutral hole defects such as deformation on both ends of the guide post, guide pin hole in the center of the heat treatment should be revised, so that a clamping will guide post two cylindrical surface grinding out, to ensure the alignment of a cylinder.

Posted by: hannahgwendolyn at 09:48 AM | No Comments | Add Comment
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