Non-Destructive Testing Technology for Steel Materials

Professional Introduction for Overseas Clients

Steel materials and steel welded structures are the most fundamental components in modern infrastructure, mechanical manufacturing, petrochemical industry, energy pipelines, bridge engineering and offshore projects. During production, rolling, forging and welding processes, various invisible defects such as internal cracks, laminations, inclusions, porosity and surface micro-cracks may occur. These tiny hidden defects cannot be found by visual checking, but will expand continuously under alternating load, vibration and corrosive environments, easily causing structural failure, fracture, leakage and major safety accidents.

Non-Destructive Testing (NDT) is the most reliable and widely accepted quality inspection technology in the global steel industry. It evaluates the integrity and internal quality of steel components without damaging the original structure, ensuring product qualification, project safety and long-term service stability.

1. Main Steel NDT Inspection Technologies

1.1 Ultrasonic Testing (UT)

Ultrasonic testing is the core method for internal defect inspection of steel plates, steel pipes, profiles and forgings. It uses high-frequency ultrasonic waves to penetrate steel materials to detect internal cracks, delaminations, slag inclusions, porosity and incomplete fusion.

UT features strong penetration depth, accurate defect positioning and high sensitivity. It is widely used for raw material incoming inspection, finished product quality verification and in-service safety inspection.

1.2 Radiographic Testing (RT)

Radiographic testing (X-ray / Gamma ray) forms intuitive internal imaging for steel welds and thin steel materials. It is highly effective for judging volumetric defects such as welding porosity, slag inclusion and incomplete penetration.

RT provides permanent inspection records and is the most authoritative inspection method for international project acceptance and export steel quality certification.

1.3 Magnetic Particle Testing (MT)

MT is specially used for surface and near-surface defect detection of ferromagnetic steel. It can quickly identify tiny fatigue cracks, grinding cracks and welding surface defects that cannot be seen by eyes.

It is widely applied for structural steel parts, bolt surfaces, weld surfaces and mechanical components inspection.

1.4 Penetrant Testing (PT)

PT is suitable for all non-porous steel materials, including carbon steel, alloy steel and stainless steel. It effectively detects all open-to-surface micro defects on complex-shaped workpieces.

It is the essential supplement for non-magnetic steel and special structural component inspection.

1.5 Advanced Phased Array & TOFD Testing

For high-standard engineering and thick-wall steel welds, we support Phased Array Ultrasonic Testing (PAUT) and TOFD technology, realizing high-precision imaging, defect sizing and quantitative evaluation to meet international high-end project requirements.

2. Inspection Coverage

Steel plate, steel coil, steel pipe (seamless & welded pipe)

H-beam, angle steel, channel steel, round steel and profiles

Steel structure welds, butt welds, girth welds

Forgings, castings, pressure vessel components

In-service structural regular safety inspection

Pre-shipment export inspection & third-party acceptance

3. International Standards Compliance

All testing operations and defect evaluation strictly follow international standards: ISO, ASTM, EN, AWS, API and GB standards.

All inspectors hold official NDT Level II qualifications. We issue CNAS & CMA accredited bilingual inspection reports, which are globally recognized for project bidding, engineering acceptance and steel export customs clearance.

4. Core Service Advantages

Full-series NDT technical solutions to achieve full coverage of internal and surface defects

Independent third-party institution with objective, fair and credible test data

Support factory batch inspection and on-site construction inspection

Strict international standard execution to meet overseas owner requirements

Fast testing cycle and standardized report delivery

5. Conclusion

Steel NDT inspection is an indispensable technical guarantee for controlling steel quality, eliminating hidden dangers and ensuring structural safety. Professional non-destructive testing effectively avoids material failure, engineering accidents and trade quality disputes.

We provide one-stop, standardized and internationalized steel non-destructive testing services for global steel exporters, engineering contractors and equipment manufacturers, helping clients stabilize quality, reduce risks and improve project value.