Magnaflux

Magnaflux Quasar is used to test many types of volume forgings, ranging from small parts such as seat belt adjusters, to large, heavy parts such as axles. Other applications include:

• Bearing components - races, hubs and rollers
• Suspension components - knuckles and control arms
• Engine components - connecting rods and camshafts
• Transmission components - shafts and gears

In all applications, Quasar detects all structurally significant defects that can affect the part's ability to function as designed and specified.

In forgings, Quasar detects all of the structural defects that occasionally appear including:

• Cracks
• Laps and Bar ends
• Double strikes
• Inclusions
• Incorrect hardening or tempering (for ferrous forgings)
• Significant non-fill
• Missing features
• Significant dimensional variation

Magnaflux Quasar provides better production NDT

Since a part's resonance pattern contains information about the structural integrity of the whole part, a single Quasar test can replace multiple NDT operations that typically focus on specific defects. In volume testing applications, Magnaflux Quasar replaces:

• Magnetic particle (cracks, laps, bar ends)
• Eddy current (cracks)
• Hardness testing (heat treat)
• X-Ray (internal defects)

It also replaces, or complements visual or white light inspection for double strikes, non-fill, missing features, and significant dimensional variation.

Special Considerations

Magnaflux Quasar testing is used for parts and materials that are stiff enough to resonate. Therefore it is applicable to essentially all forgings.

Magnaflux Quasar testing will detect only structurally significant defects - that is, defects that are severe enough to cause a part to fail prematurely in service. So Magnaflux Quasar will not detect surface discontinuities associated with parting lines or tool marks. The benefit of this is that Quasar will not reject parts that have cosmetic or superficial defects. This minimizes false rejects, maximizing yield and minimizing scrap.

Note that in bearing test applications, Magnaflux Quasar cannot detect the small cracks that sometimes occur on the face of bearing races. While these defects do not affect the structural integrity of the race, they present an abrasive surface to the bearing elements. Other NDT methods must be used for this specific defect.

Benefits

The benefits of using Magnaflux Quasar for production forgings include:

• Reliable detection of all structurally significant defects in a single test
• Results that can predict road life by correlating to failure testing (e.g., tensile or fatigue tests)
• Computer-based accept/reject decisions, not subject to human judgment
• Reduction in scrap because cosmetic defects are not rejected
• Dry, non-magnetic process eliminates need for pre- and post-inspection treatment

Forgings Economic Case Study

Description

The part is a forged steering rack tested at 180 parts per hour. The plant operates 3 shifts per day, 5 days per week and produces 900,000 racks per year. The plant is located in the US and all costs are in US$.

Magnaflux Quasar allows the current inspection regime to be modified as follows:

Magnetic particle test eliminated - saving $0.90 per part
(Note - MPI cost reflects the requirement that the part must be polished for effective inspection - Quasar eliminates the need for polishing.)

The Quasar system consists of a manually loaded Quasar 3200 Dual Test Station NDT System with error proofing procedures built into the software, and mechanical marking of accepted parts. The total price was $155,000.

The cost savings are shown in the table below.

The Quasar Cost per Part is based on capital amortization over 2 years. It does not include labor because the Quasar load/unload operation is incorporated into the existing operator cycle, with no added manpower. In addition to the reduced NDT cost, the scrap rate was substantially reduced for additional savings.