Nodularity control through velocity measurement is an established practice in plants manufacturing cast iron structural components. The aim being to measure the relative percentages of grey and ductile iron in a given part. Currently, the general practice is a manual or automatic spot test with oil coupling, but a much higher efficiency and lower overall process cost is achieved by using dry coupling, as utilised in the Autoscan 2400.

Advantages of the Autoscan 2400 over alternative products include

• Full process automation and control
• Precise and consistent transducer placement
• Dry-coupled transducer avoids couplant/oil contamination of part
• Reduces cost by eliminating couplant and cleaning
• Durable ‘IP67’ instrument enclosure
• Choice of digital or analogue outputs
• Direct read out of velocity
• User programmable alarm limits

ULTRASONIC FLAW DETECTOR

The Autoscan 2400 has been developed from the Sonatest SS240 digital flaw detector.

This proven full-featured flaw detector has been sold to more than 50 countries. When not required for in-line use, the Autoscan 2400 can be used as a portable flaw detector for a variety of industrial applications.

TRANSDUCERS & DELAY LINES

To optimise the performance of the Autoscan 2400 a specific series of transducers has been developed. The result is medium damped straight beam probes for dry coupling nodularity control with frequencies of 2 and 5MHz available as a standard. These are available as top or lateral mount microdot connectors. Suitable collars can be bought to attach the different delay lines.

Any particular application can be catered for. Depending on the thickness range of the component at the test area, there are a range of state of the art delays of differing dimensions available: interchangeable spherical, rounded tip cylindrical or thin flat

The specific design of the delay has been developed for optimum coupling, acoustic impedance matching and durability under challenging mechanical and environmental testing conditions on rough casting surfaces. A set of spare delay lines is included with the standard Autoscan 2400 package.

BENEFITS & FEATURES

ADDED FUNCTIONS

The unit is mains powered, with a front proportional output connector and a velocity measurement mode function, allowing both on-screen display of the measured acoustic velocity value and an analogue or digital output. Alarm threshold setting for acoustic velocity is possible.

SET-UP AND SYSTEM INTEGRATION

The system can be easily integrated into current and new production lines for automatic nodularity control, transmitting the relevant output signals to the relevant PLC or visual indicators (ie. a lightbox) or to a networked or independant digital control system.

Improvement of reliability: Ensures traceability, consistency and repeatability of ultrasonic tests.

Wider quality control scope: Faster inspection allows testing of a much larger number of spot welds and in-line inspection allows test of spot welds on each individual component.

Weld process monitoring: Real-time full availability of data on each component passing through the line for statistical analysis and control.

Cost saving: Avoids off-line tests, eliminates cost of manual inspection, reduces line stops and decreases wastage by faster identification of faults.

• In-line inspection of a user programmed sequence of spot welds in series within current cycle times or of a selected set of critical spot welds in each part
• Automatic positioning, orientation and evaluation utilizing an integrated vision system
• Automatic integrity evaluation of spot weld by means of ultrasonic testing
• Customised real-time data processing for communication to the line quality control for monitoring, weld process control and part rejection
• Automatic data storage in a data base for statistical analysis and recording of process history

Operation: The test sequence can be defined independently for different parts that pass through the line according to the particular plant strategy and the Q.A. requirements.

The ultrasonic test set-up, as well as the applicable warning and rejection thresholds, can be defined for each individual spot weld.

EVALUATION AND MONITORING

Specific software provided as part of the basic system components evaluates the result automatically and classifies the spot weld into one of five categories: good spot weld; too small; stick weld; loose weld or burnt weld.

After each test all data are readily available and are also stored in a relational data base in a MS Excel compatible format. Together with pre-existing data such as the part reference, spot and weld gun identification, actual welding parameters, etc. the results can then be processed for monitoring, traceability and actions.