Technology developed at Coppe enhances pipeline safety and strengthens the competitiveness of Brazilian industry
Planeta COPPE / Metallurgical and Materials Engineering / News
Date: 17/08/2026
Small cracks that form in metallic materials can involve truly complex phenomena and propagation mechanisms. In pipeline steel, for example, secondary cracks or delaminations may form perpendicular to the plane of another crack—the primary one—creating internal separations that make it difficult to assess the material’s mechanical behavior. Although they measure only a few millimeters, these separations can directly affect the safety and performance of structures used in strategic sectors, such as the oil and gas industry.
To overcome this challenge, researchers from the Metallurgical and Materials Engineering Program (PEMM) at Coppe/UFRJ have developed advanced techniques that allow for a more precise understanding of this phenomenon and a more reliable assessment of the crack-propagation resistance of the steels used in pipeline manufacturing.
The research is part of Sergio Luis Gonzalez Assias’s doctoral thesis and focused on the study of internal separations within steel layers caused by separations perpendicular to the main crack. Technically known as splits—or delaminations perpendicular to the crack plane—this phenomenon can significantly alter the results of mechanical tests and, in some cases, lead to the rejection of materials that, in practice, would be suitable for use in piping.
This type of inappropriate material rejection has significant economic impacts in the industry, increasing production costs, limiting the use of materials, and reducing the competitiveness of a sector that is essential to the country.
The experiments, conducted at PEMM’s Fracture Mechanics Laboratory (LMF), made it possible to establish unprecedented criteria for evaluating the fracture toughness of steels—that is, their ability to absorb energy and resist crack propagation before fracture. The research combined high-precision experimental techniques with advanced numerical modeling, expanding our understanding of the effects of splits and making material qualification processes more reliable.
“Fracture mechanics tools are designed to determine critical operating conditions. These include, for example, the critical pressure, the minimum operating temperature, and the maximum acceptable crack size in the structure. In other words, the focus is not on predicting crack formation, but on defining safe operating limits so that, even in the presence of unavoidable discontinuities, the pipeline operates without the risk of failure due to unstable crack propagation,” explains Sergio.
In addition to its scientific contribution, this research is of great technological relevance to Brazil. By refining the methods used to evaluate materials employed in pipeline systems, the study increases the reliability of analyses, reduces technical uncertainties, and prevents economic losses resulting from the unnecessary replacement of materials. As a result, it helps keep Brazilian industry aligned with the highest international standards of quality, safety, and innovation.
According to Sergio, these techniques can be applied to the characterization of materials used in various types of rigid pipelines for the extraction, production, and transportation of oil, natural gas, and other fluids. “On an industrial scale, it is impossible to manufacture a structure that is completely free of discontinuities or cracks. Our work contributes to a better characterization of the materials used in the manufacture of pipelines, ensuring a more accurate assessment of crack propagation resistance. Therefore, the critical aspect is not the formation of cracks themselves, but the material’s ability to resist their propagation”, he states.
Titled “Effects and treatment of splits on the fracture toughness of steels for oil and gas piping” (Efeitos e tratamento dos splits na tenacidade à fratura de aços para tubulações do setor de petróleo e gás), the thesis was supervised by PEMM Professor Hector Kotik and collaborating Professor Juan Elías Perez Ipiña. The thesis was selected to represent PEMM in the national round of the 2026 Capes Thesis Award.
