EoW November 2009

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EuroWire – November 2009 59
Testing & measuring
Detecting flaws and conditions
Since 1928, MAC has provided eddy current, ultrasonic, and flux leakage test systems customised to meet mill and customer
standards. For inspecting wire, eddy current is generally the method of choice for in-line testing with cold heading operations such
as spring making, parts forming, checking continuity, alloy and other conditions. Eddy current tests are also frequently used to locate
welds and splices in insulated cable.
MAC instruments can handle a range of metal wire
including cut lengths, continuous production,
stranded, multi-conductor, cold drawn, fine
diameter, and insulated cable. Carbon steels,
stainless alloys, copper, aluminium, titanium and
other non-ferrous metals can be inspected.
MAC offers rotary and coil eddy current
equipment depending on the nonconforming
conditions and the size and characteristics of the
material.
For example, the MultiMac electronics and rotary
probe can detect long continuous surface and
subsurface defects such as seams and welds,
while short defects such as cracks and laps are
detected using encircling or segmented test coils.
By using the Varimac or production comparator
eddy current testers, alloy differences, hardness,
and heat treatment may be detected in cut
lengths or continuous wires.
Additional items such as markers, controls, demagnetisers and components for mounting the coils or rotaries, and positioning and
driving the material through the test, are combined with the instrumentation to make up a complete test system.
Magnetic Analysis Corp – USA Fax: +1 914 699 9837 Email: Website:
MultiMac probe fromMAC ▲ ▲
Upset testing equipment
Wire rod for cold shaping in accordance with EN 10263 and/or DIN 1654 has been
tested for many years by standardised compression tests. From the European point of
view the method is adequate when the test specimen is compressed by the ratio 1:3.
In the past year, Friedrich Petig GmbH has supplied what is believed to be the largest
upset testing machine in the world to date to a Korean customer, Pohang Steel
Corporation (POSCO).
POSCO rolls wire for cold shaping (cold heading) in many qualities to 1,200 N mm²
tensile strength. The largest diameter is 55mm. The machine consists of a double press,
which is accommodated in a common framework.
The wire to be examined is cut in a plane parallel manner to a length of 1.5 x diameter
on the right press side with 3,500kN shearing force in a double shear tool. The test
specimen is then upsetted to a third of the initial length on the left press side with
6,000kN compression force.
In related photo documentation the upset test specimen is photographed all around
from four sides, and displayed on a 19" screen. The cracks that may arise during the
rolling process, which have become visible through the rolling, can thus be easily
documented. A PC is installed for control support.
The values in accordance with DIN and ASA, compression extent pre-selection,
speed, and documentation can be entered here.
Friedrich Petig GmbH – Germany
Fax: +49 2181 73108
Email:
Website: