Council urges review of IF products

Report finds steel bars may be weaker

The Asean Iron & Steel Council (AISC) has called for a review of the use of induction furnace (IF) technology in the production of reinforcing steel bars across Southeast Asia, citing concerns over structural safety.

The recommendation was made in a statement accompanying a technical paper prepared by the council's Steel Product Committee, which examines different steelmaking technologies and calls for national standards to be updated in line with scientific knowledge.

The paper draws on research by Assoc Prof Porntep Punnarak of the Institute of Aquatic Resources, Chulalongkorn University, together with findings by Assoc Prof Dr Nurulakmal of Universiti Sains Malaysia. The studies compared reinforcing bars produced using blast furnace/basic oxygen furnace (BF/BOF), electric arc furnace (EAF) and induction furnace technologies.

Steel produced through the induction furnace route generally recorded higher levels of non-metallic inclusions than steel produced by BF/BOF and EAF routes when assessed using the K4 cleanliness index, the report said.

The paper said these microscopic inclusions "may reduce ductility, fatigue resistance and overall structural performance", although it also noted that IF-produced steel can comply with existing chemical composition requirements under current national standards.

The K4 cleanliness index is used to evaluate the quantity and distribution of non-metallic inclusions within steel.

The report argues that while conventional standards largely assess tensile strength, yield strength and chemical composition, they do not routinely require cleanliness testing capable of identifying differences in steel produced through different manufacturing routes.

The paper says many steel standards adopted across Southeast Asia were developed decades ago, before induction furnace technology became widely used for the manufacture of reinforcing bars.

As a result, the council argues, existing regulations may not fully reflect advances in steelmaking technology or incorporate newer methods of assessing steel quality.

The council also pointed to regulatory developments elsewhere. It said China prohibited the use of induction furnaces for reinforcing bar production in 2017, while India, Malaysia and several other jurisdictions have strengthened regulatory oversight of IF-produced reinforcing steel.

Thailand requires reinforcing bars to be marked according to their production route, including BOF, EAF and IF, to improve product traceability.

Referring to the collapse of the State Audit Office building in Bangkok following the March 2025 earthquake centred in Myanmar, the council said the incident "underscores the urgent need to reassess construction material standards and ensure that steel used in critical infrastructure meets the highest levels of quality and reliability."

However, the technical paper does not conclude induction furnace-produced steel caused the building's collapse.

Instead, it argues that recent structural failures highlight the importance of reviewing engineering standards and construction materials as new scientific evidence becomes available.

Rather than calling for an immediate ban, the council recommended that governments undertake scientific reviews of existing standards governing reinforcing steel.

It said regulators should consider introducing additional quality tests, including steel cleanliness assessments where appropriate, and evaluate whether induction furnace technology should continue to be used for structural applications or be limited to non-critical uses.

"The use of induction furnace technology for structural reinforcing steel should be critically reviewed," the paper says, adding public safety should remain the overriding consideration when setting technical standards.