How to inspect the big bearing rings with cementite surface
We want to inspect the inclusion in the area of 5 to 6 mm, but the cementite layer is about 3 to 4 mm, when we inspect the rings with the ultrasonic, the noise is very higher when the ultrasonic wave propagate in the cementite layer, because the difference of the baise material and the surface material, how to inspect it? Thank you!
04:32 Aug-27-2009 S.V.Swamy Engineering, - Material Testing Inspection & Quality Control Retired from Nuclear Fuel Complex , India, Joined Feb 2001 783
Re: How to inspect the big bearing rings with cementite surfaceIn Reply to Boka at 09:28 Aug-26-2009 (Opening).
Why not try from the other side? Bearing rings are usually hardened from the inside (ID side) because that is the bearing surface. The other material is in spheroidized annealed condition,w which is quite amenable for ultrasonic testing. Am I missing something? Could you please give more details? I am interested because I was directly involved in inspection of bearing steel billets, mother blanks, tubes and rings at one time.
Re: How to inspect the big bearing rings with cementite surfaceIn Reply to S.V.Swamy at 04:32 Aug-27-2009 .
Thank you for your reply, Yes, We inspected from the other side of the rings when one side is important, We need to inspected the whole ring, But the cementite layer is also important, So how to distinguish the signal of defect hide in the noise of the cementite layer? If we use the low frequency probe, It would be difficult to find the small defect. If we use the higher frequency probe ,the noise would disturb the inspection. The same job area, I am very glad to discuss with you. Thank you!
00:38 Aug-29-2009 S.V.Swamy Engineering, - Material Testing Inspection & Quality Control Retired from Nuclear Fuel Complex , India, Joined Feb 2001 783
Re: How to inspect the big bearing rings with cementite surfaceIn Reply to Boka at 09:13 Aug-27-2009 .
Thank you. All the UT is done on the billets or mother blanks (Ball Bearing Steel Tubes) before the tubes are cut into rings. If it is of much larger diameter, a ring forging route is generally followed (but I have no personal experience with that route). We were producing pipes / tubes of up to nearly 200 mm ID (I am talking from memory since we stopped this line long ago). The rings are inspected at the bearing manufacturer after hardening and grinding visually and through FPT (Fluorescent Penetrant Testing). I am not aware of their doing UT at that stage.
We were doing inclusion control through microscopic / macroscopic examination of a sufficient number of samples and of course the billets / blanks will show up the big inclusion during a UT examination. For billets, the frequency would be in the 2 to 5 MHz range and for blanks we were using 5 to 10 MHz on an automated immersion testing system. Since I am writing from memory, the actual values could be slightly different.