Material of centrifugal pump shaft
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The material of the pump shaft in centrifugal pumps is usually 45#, or maybe 304? Does the pump shaft come into direct contact with the medium? Can some highly corrosive media corrode the pump shaft?
Just look at the structural diagram of the centrifugal pump – if there is no leakage, the pump shaft generally won’t corrode.
This depends on the structure of the pump; if gaskets or O-rings are present between the impeller nut, the impeller, and the shaft sleeve to protect the shaft, then the material of the shaft does not need to meet corrosion resistance requirements. If in direct contact with the medium, corrosivity must be taken into account. Generally, the torque that stainless steel shafts can transmit is lower than that of 4140 and 12%Cr materials. The strength of the shaft needs to be considered.
Pump shafts generally don’t use 304 steel; the most common material is 45 steel, which is not corrosion-resistant. If corrosion is a concern, 2Cr13 is used
The material used for the pump shaft depends on your medium; we have many shafts made of stainless steel available
Taking the cantilever pump, which has a relatively simple structure, as an example, there are two types: one with a bare shaft (which is in direct contact with the material) and another with a shaft sleeve (where the shaft sleeve is in contact with the material). The shaft sleeve mentioned here is not the kind used in modular mechanical seals. In the case of a bare shaft, it is necessary to consider the impact of the material on the choice of shaft material. According to the material selection requirements specified in API610, stainless steel can be used for the shaft. However, in practical engineering applications, users or design firms take into account the strength requirements of the shaft and choose materials with higher strength; for example, 4140 steel is used for shafts in carbon steel housings, while duplex stainless steel is used for those in stainless steel housings. In the case of a shaft with a sleeve, 4140 is generally used for the shaft, while the material choice for the sleeve depends on the effects of the surrounding materials.
We have shafts made of 316 and 316L materials; the choice is based on the properties of the medium.
45# steel can be quenched and tempered； 304 cannot be used ； Important shafts can use 40Gr.