The aim of this work is to show the advances in the study of Acoustic Emission (AE) produced during deformation and crack propagation in seamless steel tubes.

Test pieces are rings, cut in transversal mode from seamless steel tubes. A small part of them is eliminated to enable they can be introduced in a simple machine, specially constructed to open them. AE produced during ring opening is captured by three AE transducers. Two of them (200 kHz resonant frequency) act as "guards", and the third (Wide Band) registers the true AE.

Force handy exerted is measured by a small load cell specially constructed. AE parameters, load and separation of force application points are registered by AEDOS system.

Different type of tests pieces are used. Some in their natural form (with oxide), others without oxide, and others with cracks induced.

AE parameters: Amplitude, Duration and Rise time and studied. Also spectral analysis of digitized AE signals and statistical analysis are carried out.

It is necessary to say that results showed here are only a small part of a larger research begun one year ago.