EMAT measurement of ductile cast iron nodularity

Details EMAT measurement of ductile cast iron nodularity EMAT measurement of ductile cast iron nodularity

1994-09-30

1998-02-03

Williams, Hezron E.

Measuring and testing

Vibration

By mechanical waves

73643, 73598, G01N 2918, G01N 2900

Patent

active

057146888

ABSTRACT:
A method of examining a ductile iron casting to determine a percent of nodularity present in the casting uses an electromagnetic acoustic transducer (EMAT) system to determine a time-of-flight of an ultrasonic shear wave pulse transmitted through the casting at a selected location, from which a velocity of sound in the casting can be determined. The ultrasonic shear wave pulse created and sent through the casting experiences several internal reflections within the casting, and the absolute delay time for both second, T.sub.DELAY1, and third, T.sub.DELAY2, multiple reflections are used to determine the time, T.sub.DELTA, required for the ultrasonic pulse to travel through twice the thickness, t, of the casting at said location. The velocity, V.sub.SHEAR, of the ultrasonic shear wave pulse through the casting is calculated from T.sub.DELTA and a measurement of the thickness, t, of the casting at the location being inspected. The percent of nodularity of the casting is determined from a pre-established relationship between the calculated shear wave velocity, V.sub.SHEAR, and the percent of nodularity for ductile cast iron.

REFERENCES:
patent: 3603136 (1971-09-01), Diamond et al.
patent: 3690155 (1972-09-01), Eichler
patent: 3774444 (1973-11-01), Kent
patent: 3844163 (1974-10-01), Di Leo
patent: 3848460 (1974-11-01), Bantz et al.
patent: 4114455 (1978-09-01), Walker
patent: 4307616 (1981-12-01), Vasile
patent: 4348903 (1982-09-01), Sato et al.
patent: 4568388 (1986-02-01), Dremann et al.
patent: 5035143 (1991-07-01), Latimer et al.
patent: 5172591 (1992-12-01), Bohon
patent: 5216921 (1993-06-01), Tsuboi
patent: 5299458 (1994-04-01), Clark, Jr. et al.
G.J. Parkinson et al., "Non-Contact Ultrasonics", Jul. 1977, pp. 178-184.
Beissner, R.E., "Electronmagnetic--Acoustic Transducers A Survey of the State of the Art", Jan., 1976.
Metals Handbook , 9.sup.th Edition, .COPYRGT.1989, ASM International, pp. 532-35.
Henderson, H.E., "Ultrasonic Velocity Technique for Quality Assurance", Foundry Trade Journal v136 n 2985, Feb. 21, 1974, pp. 203-09.
Rickards, P.J. "Progress in Guaranteeing Quality Through Non-Destructive Methods of Evaluation," UK Official Exchange Paper, The Foundryman International, pp. 196-209, 1987.

Affiliated with

Also associated with

Rating

EMAT measurement of ductile cast iron nodularity does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with EMAT measurement of ductile cast iron nodularity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and EMAT measurement of ductile cast iron nodularity will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-664248