1, material
selection
The choice of
material of stainless steel powder metallurgy parts, in addition to the
mechanical properties, should also to select the raw powder of the species and
its composition, the density of the material, sintering conditions and
subsequent processing in accordance with the requirements of part of
wear-resistant, corrosion resistance and other characteristics.
Although, in
high alloy powders as raw materials by material of high density and sintering
conditions, or the carburizing and quenching heat treatment, the physical and
mechanical properties of stainless steel powder metallurgy parts material
increased, but parts of the production cost also correspondingly increased.
Therefore, in the selection of materials, it is best not to pursue the
excessive material properties, and increased production costs.
2, shape design
Stainless steel
powder metallurgy structural parts are generally made of metal powder with
single axial compression, so the shape of the parts are subject to various
restrictions. When designing parts, we must pay attention to overcome these
limitations, so as not to increase the production cost of parts or produce
quality problems. In addition, the clever use of combination or sintering
method, such as the legitimate, but also to overcome some of the limitations of
the shape of the parts.
In addition,
some parts of the shape of cutting and other methods can not or difficult to
make, but it is suitable for stainless steel powder metallurgy process. Such
examples are many, such as tooth in motor pulley, the transmission synchronizer
gear hub etc.. This kind of parts fully embodies the characteristics of
stainless steel powder metallurgy technology.
3, size accuracy
Generally
speaking, although can be made very high dimensional accuracy of green
compacts, but due to shrinkage or swell produced in the sintering process,
powder metallurgy parts size precision reduced. When the size precision of
stainless steel powder metallurgy parts can not meet the technical
requirements, it is necessary to increase the finishing, cutting, grinding and
other follow-up processing. Therefore, to determine the size accuracy of parts,
to master the allowable size of each process accuracy, as far as possible to
reduce the number of processing procedures, in order to reduce the production
cost of parts.
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