How to reduce product defects in plastic pipe fittings […]
How to reduce product defects in plastic pipe fittings
Improve the cooling conditions during grinding, such as the use of oil-impregnated grinding wheels or internal cooling wheels. The cutting fluid is introduced into the center of the grinding wheel, and the cutting fluid can directly enter the grinding zone to exert an effective cooling effect to prevent the surface of the workpiece from being burned. Reasonable use of cooling lubricants, play the three major functions of cooling, washing and lubrication, keep the cooling and lubrication clean, and thus control the grinding heat within the allowable range to prevent thermal deformation of the Xinuo plastic pipe mold parts.
The quenching stress after heat treatment is reduced to a minimum, because the quenching stress and the reticulated carbonized structure under the action of the grinding force, the phase change of the structure is extremely easy to cause cracks in the workpiece. For high-precision molds, in order to eliminate the residual stress of grinding, low-temperature aging treatment should be performed after grinding to improve the toughness.
To eliminate the grinding stress, the mold can be immersed in a 260-315 ° C salt bath for 1.5 min, and then cooled in 30 ° C oil, so that the hardness can be reduced by 1 HRC, and the residual stress is reduced by 40% to 65%.
For precision grinding of plastic pipe molds with a dimensional tolerance of 0.01 mm or less, attention should be paid to the influence of ambient temperature, and constant temperature grinding is required. It can be seen from the calculation that for a steel piece with a length of 300 mm, the material has a change of about 10.8 μm at a temperature difference of 3 ° C (10.8 = 1.2 × 3 × 3, and the deformation amount per 100 mm is 1.2 μm / ° C), and each finishing process needs to be fully considered. The impact of this factor.