Selection of stainless steel shaft for linear motion application
If you are facing scoring mark issue in your existing stainless steel linear guide solution then you are reading a right article.
People are using SS linear guide solution mostly in pharmaceutical, packaging & chemical industry where highly corrosive substances are coming in directly contact with system.
Stainless steel corrosion resistance is a result of a very thin (about 5 nm) oxide layer on the steel’s surface. The passive layer forms because of the minimum 10.5%chromium added to stainless steel. Other elements such as nickel, manganese, and molybdenum can be added to enhance stainless steel corrosion resistance. Carbon content is less than 1.5% in SS and because of that hardness is also less.
304 and 316 SS grade austenitic stainless steel are used in linear motion application but because of less hardness it is not recommendable to use with recirculating ball bearing where ball hardness is 58 HRC. Martensitic SS with 0.1 to 1.2% carbon content like 440C grade is developed for linear guide application but again in long term or high acceleration application, recirculating balls are damaging the shafts.
One alternate solution is to shift to polymer based linear bearing where polymer will come in contact with rod and scoring mark issue can be completely resolve even in case of high acceleration application. Igus has developed special material A160 for SS mating part, The COF of this material against X90 or V2A is very less and it is advisable to use with soft and hardened stainless steel shaft both. If you are facing scoring mark issue with your current stainless steel shaft change your bearing not shaft.
To know more in detail. Check below link or contact me at arai@igus.net