Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Grinding and Corrosion Resistance 4

Status
Not open for further replies.

harlequinir

Chemical
Joined
Oct 23, 2003
Messages
8
Location
US
Can changing the speed during a diamond turning (cutting) operation on 400-series stainless steel change its corrosion resistance? It seem if we cut at a higher rpm the tool is more suseptable to acids.
 
Diamond tools are not usually used to cut iron based materials as the iron has an affinity for dimond(which is, of course, cubic carbon). The higher the cutting speed, the hotter the diamond cutting edge is and the more rapidly the diamond will diffuse into the iron.

A good alternative is CBN tools.
 
Regardless of the cutting or abrading tool chemistry, you will get some degradation of corrosion resistance from surface cold work. This arises from residual stress and exposure of inclusions. As an example, polishing stainless steel with 120 grit alumina to produce the familiar brushed appearance causes a loss of corrosion resistance equal to the difference between 304 and 316, quite a bit!
 
The effect of smeared metal, exposed inclusions and possible imbedded material all lower the corrosion resistance. If it must be restored a chemical passivation is needed.
Wet grinding causes the least loss of corrosion resistance.

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top