Magnetic Particle Testing in Steel & Primary Metals: What It Finds, What It Misses, and What Governs It

What MT is actually used for in steel & primary metals

Rolls, couplings, hooks and lifting equipment in a steel plant are examined with MT on statutory and maintenance cycles.

How MT works

MT magnetises a ferromagnetic component and applies iron particles, which gather at the flux leakage a surface-breaking or near-surface discontinuity creates. It is fast, inexpensive per square metre, and unusually good at what it does: finding cracks in steel that a visual examination would miss.

What MT will not do

What MT will not do: work on non-magnetic material at all — no stainless austenitics, no aluminium, no nickel alloys — and it finds nothing meaningfully below the surface. Coatings degrade sensitivity, and flaws parallel to the flux direction are invisible, which is why examination in two directions is standard practice rather than diligence.

The steel & primary metals assets this applies to

Continuous casters, rolling mills and their rolls, furnace shells and ducting, cranes, and the plate, bar and tube the mill produces.

The damage mechanisms driving the examination

Product soundness — laminations, inclusions and surface defects — alongside plant-side thermal fatigue, wear, and structural fatigue in heavily loaded cranes and mill housings.

What governs acceptance

Product examination runs to ASTM and customer specifications, often inline and automated; plant maintenance examination runs to ASME and jurisdictional requirements. On the method side: ASME Section V Article 7; AWS D1.1 for structural work; ASTM E1444 in aerospace and general industry; ASTM E709 as the practice reference. An examination that is technically sound but performed outside the governing regime is not an examination anyone will accept, which is why the code family matters as much as the technique.

How Atlantis delivers MT in this sector

Atlantis mobilises examination teams to your site under Atlantis procedures with ASNT Level III oversight — we do not claim a depot or laboratory in every market, and say so plainly. What you receive is the examination performed to a qualified procedure, findings evaluated against the acceptance criteria your contract names, and records structured to survive a client audit years later.

Magnetic Particle Testing services · MT training and certification · Steel & Primary Metals NDT training · scope a MT examination.

MT in other sectors

Refining · Petrochemical · LNG · Offshore · Pipeline · Marine & Shipbuilding.

Other methods in steel & primary metals

UT · RT · PT · VT · ET.

What Atlantis provides in Steel is set out in full on the magnetic particle testing services page — wet fluorescent and dry powder examination on ferromagnetic welds, castings and fatigue-critical details.