Why You Cannot Regrade EN 10025 JR Material to J2 Material With Charpy Impact Testing

Webinar details

This webinar tackles a widespread but dangerous industry myth: that EN 10025 JR steel can be “upgraded” to J2 simply by passing a few low-temperature impact tests. It explains, in clear metallurgical terms, why this is fundamentally flawed. JR and J2 are not interchangeable grades, they are produced differently at a microscopic level, with J2 specifically engineered for reliable performance at -20°C, while JR is only qualified at +20°C. The webinar shows how differences in deoxidation, inclusion content, grain structure, and manufacturing processes result in vastly different and inconsistent toughness behavior, meaning a single passing test does not guarantee real-world performance.

More importantly, it highlights the real-world consequences: structural failure risk, non-compliance, and potentially catastrophic outcomes when materials behave unpredictably in cold or dynamic conditions. The message is blunt, this practice is common, but it is technically wrong and “highly dangerous.”

This webinar is essential for engineers, fabricators, QA professionals, and anyone specifying or testing structural steel. It doesn’t just explain the theory; it exposes a risky industry habit and replaces it with sound metallurgical understanding. If your work involves compliance, safety, or liability, this session gives you the knowledge to challenge bad practices, protect your projects, and make defensible engineering decisions.

• The webinar will be recorded and will be sent out to registered attendees afterwards.
• A certificate of attendance will be provided to attendees who request one near the end of the live webinar session.
• Please note: the time stated on this event is in UTC. You will need to convert this to your own time zone.

Key takeaways from this webinar

•  JR ≠ J2 – they are fundamentally different materials: The difference is not just a test temperature. J2 steel is manufactured to achieve reliable toughness at -20°C, while JR is only qualified at +20°C. This comes from differences in metallurgy (grain structure, inclusions, deoxidation), not something you can “fix” afterward.
• Passing a Charpy test does NOT upgrade the material: A single (or even a few) impact test results do not represent the full variability of the material. JR steel can occasionally pass J2 test conditions by chance, but this does not mean it will behave consistently in service.
• Variability and unpredictability are the real risks: JR material has a much wider scatter in toughness at low temperatures. Even if one sample performs well, another from the same batch may fail. That unpredictability is the core danger.
• Regrading is technically incorrect and non-compliant: Reclassifying JR as J2 based on testing alone goes against the intent of EN 10025 and proper material certification practices. It creates a false sense of compliance.
•  The consequences can be severe: Using incorrectly regraded material can lead to brittle fracture, especially in cold or dynamic loading conditions, potentially resulting in structural failure.
•  This is a common but risky industry practice: The seminar emphasizes that this happens more often than people admit, which makes awareness and proper understanding even more important.
• Bottom line: You cannot “test your way” from JR to J2. If you need J2 performance, you must specify and procure J2 material from the start.

Related courses

This webinar/topic relates to our school of Mechanical Engineering and is particularly found in the following courses:

• Professional Certificate of Competency in Advanced Plant Maintenance and AI-Driven Predictive Technologies
• Bachelor of Science (Mechanical Engineering)
• Graduate Certificate in Mechanical Engineering
• Master of Engineering (Mechanical)

About the presenter

Dr Janet Cotton, PhD, Pr Eng, Managing Director and Owner of One Eighty Materials Engineering Solutions

From the moment she launched One Eighty Materials Engineering Solutions at just 28 years old, Dr Janet Cotton has been rewriting the rules of engineering in Africa. What began as a bold idea to bring engineering rigor to real-world problems has grown into Africa’s most widely scoped ISO 17025:2017-accredited materials and metallurgical testing laboratory, a technical powerhouse trusted by industries across the continent and around the globe.

Janet is more than a founder; she is a pioneer of industrial resilience and forensic engineering. Under her leadership, One Eighty has become the go-to name for solving the toughest engineering challenges, from catastrophic component failures to complex materials selection problems, helping businesses protect infrastructure, save costs and de-risk major capital projects.

Recognizing the urgent need for technical leadership on the continent, Dr Cotton conceived and propelled the Root Cause Analysis Africa (RCA Africa) conference — the first forum of its kind dedicated to failure investigation, materials engineering and risk mitigation in Africa’s industrial ecosystem. This landmark event brings together engineers, insurers, legal experts, financiers and asset managers to build the technical capacity our economies so desperately need.

Her vision continues to shape the 2nd RCA Africa Conference, creating a platform where collaboration catalyzes innovation, resilience and sustainable growth for African infrastructure and industry.

As a driving force behind Materialia Africa et al., a leading engineering publication that highlights cutting-edge developments, conferences and case studies, including cover features celebrating the transformative RCA Africa movement — Janet has put materials science at the heart of Africa’s industrial narrative. Her leadership in editorial direction, strategic insight and technical storytelling is shaping how the continent talks about engineering excellence.