06:57 Apr-04-2003 Godfrey Hands Engineering, PRI Nadcap, United Kingdom, Joined Nov 1998 286
Re: Ultrasonic equipment for testing of billets. : Is there any automatic ultrasonic equipment on the market that can detect defects in material of a billet/roller which is hardened and ground? . Dear Mikael, Ultrasonics can certainly detect defects inside billet material and also inside rollers.
Working for SKF, I assume that you are trying to detect very small defects. High Frequency Ultrasonics (e.g. 80 MHz) can detect Oxide inclusions that are alarger than about 40 Microns diameter, and located between about 0.8 and 2.0 mm beneath the ground surface. This is in a laboratory.
In production, and when you are talking about Rollers (I assume that you refer again to Inclusion type defects), larger defects will be detectable, probably from 0.1 mm diameter, and a few tenths of a millimetre long.
Please contact me directly for more information. Godfrey@hands-ndt.co.uk
For automated applications, we can also recommend Quasar Resonant Inspection for inspecting rollers. There is a precedent for this within your own company. I will discuss this with you privately, as some of the information is Proprietory to SKF..
07:13 Apr-04-2003 Joe Buckley, Sonatest PLc Consultant, ASNT L-III, Honorary Secretary of BINDT Level X NDT, BINDT, United Kingdom, Joined Oct 1999 515
Re: Ultrasonic equipment for testing of billets. Billets and finished rollers are normally inspected in different ways.
Many different methods are used to verify bearing quality. Material quality should always be checked as early as possible - before money is put in. As a general rule Ultrasonics (and possibly other methods) are used to verify quality of the material before it is cut up and made into rollers. Defects appearing later in the process are most commonly the result of cracking during heat treatment or grinding. Eddy current inspection is likely to more appropriate at this later stage.
: Is there any automatic ultrasonic equipment on the market that can detect defects in material of a billet/roller which is hardened and ground? .