Pickling & passivation for stainless steel investment castings
Pickling&passivation is a common surface treatment way for stainless steel investment castings.It is a chemical process to remove surface oxidation of stainless steel castings.
As black or yellow scale cinder are easily produced during machining process of stainless steel investment castings,in order to improve the appearance and corrosion resistance,we must do pickling&passivation treatment for stainless steel investment castings after machining.Removing the scale cinder after welding or machining,will make castings shining and form a layer of oxide film with chromium as the main material.It will not produce secondary oxygen corrosion,achieve passivation,so as to improve the surface anti-corrosion quality of the stainless steel castings,thus prolong the service life.
Pickling passivation is generally handled by pickling passivation paste and pickling passivation solution.Pickling passivation paste carry on pickling and passivation at the same time,finish just one step,change the traditional pickling and passivation process,simple operation,and low cost.Suitable for large area coating operation.Pickling passivation solution is suitable for soaking operation of small stainless steel investment castings.
Pickling passivation is suitable for 200 series,300 series,400 series stainless steel investment castings,widely used in chemical,pharmaceutical, paper making industry,food machinery, ect.