Introduction of Coating for Powder Metallurgy Tap

Release time:

2022-10-13

Coating steam oxidation of powder metallurgy taps: After the powder metallurgy taps enter high temperature water vapor, a layer of oxide film is formed on the surface, which has good adsorption on the coolant and can reduce friction. At the same time, it prevents the bonding between the tap and the cutting material. Suitable for processing low carbon steel.

Coating steam oxidation of powder metallurgy taps:powder metallurgy tapAfter entering the high temperature water vapor, a layer of oxide film is formed on the surface, which has good adsorption on the coolant, can play a role in reducing friction, and at the same time prevent the bonding between the tap and the cutting material, which is suitable for processing low carbon steel. Nitriding treatment: tap surface nitriding, the formation of surface hardening layer, suitable for processing cast iron, cast aluminum and other materials on the tool wear. Steam nitriding: the advantages of the above two.

The coating is golden yellow, the coating hardness and lubricity are good, and the coating adhesion is good, suitable for processing most materials. Blue-gray coating, hardness about 3000HV, heat resistance 400°C. Dark yellow coating, with excellent coating hardness and lubricity, suitable for processing most materials. Blue-gray coating, hardness 3300HV, heat resistance up to 900°C, can be used for high-speed processing. Silver gray coating, superior lubrication performance, mainly used for processing non-ferrous metals. The coating of powder metallurgy taps has a significant impact on the performance of the tap, but at present various manufacturers and coating manufacturers cooperate with each other to study special coatings. Cooling conditions: For powder metallurgy taps, especially extruded powder metallurgy taps, the coolant requirements are lubrication and GT; cooling; in actual use, it can be formulated according to the conditions of the machine tool (when using emulsion, the recommended concentration is greater than 10%).

The processing parameter speed of powder metallurgy taps is based onpowder metallurgy tapThe type, material, processing materials and hardness, tap equipment to give the advantages and disadvantages. Usually according to the parameter selection given by the powder metallurgy tap manufacturer, the speed needs to be reduced in the following situations: poor rigidity of the machine tool; large faucet beating; insufficient cooling; uneven material or uneven hardness in the welding area, such as solder joints; tap lengthening or use extension Rod. Manual operation, such as bench drill, rocker drill, etc.

Some techniques for selecting powder metallurgy taps, the tolerances of powder metallurgy taps of different precision grades, the selection basis: not only the precision grade of the tap must be selected and determined according to the precision grade of the processed thread, the material and hardness of the processed workpiece; tapping equipment (Such as machine conditions, clamping handle, cooling environment, etc.); the accuracy and manufacturing error of the powder metallurgy tap itself. For example: processing 6H thread, in the steel processing, can choose 6H precision tap; in the process of gray cast iron, because the middle diameter of the tap wear faster, the expansion of the screw hole is small, so it is appropriate to choose 6HX precision tap, the service life will be better.

Cutting tap OSG adopts OH precision system, which is different from ISO standard. OH precision system will force the width of tolerance zone from low limit to every 0.02MM as a precision grade, named OH1, OH2, OH3, etc. The extrusion tap OSG adopts RH precision system. RH precision system forcibly applies the whole tolerance band width from the low limit, and every 0.0127MM is a precision grade, named RH1, RH2, RH3, etc. Therefore, when replacing OH precision taps with ISO precision taps, 6H should not be considered to be approximately equal to OH3 or OH4 levels.