ABSTRACT Automotive car companies are using AHSS (advanced high strength steels) over the last 20 years to reduce vehicle weight and improve safety. The new steels can achieve higher strength and good fatigue resistance, but some issues related to springback and low formability are also a big concern. Thus, companies need to ex- tend their know-how regarding material behaviour, design rules and manufacturing processes. Therefore, materials characterization laboratories are working to obtain the new formability charts of the steels. The grid laser marking of test pieces is a recent approach. However, the marking process must accomplish three main aspects: indelibility during the tensile testing procedure, precision, and of course, it must not affect the mechanical properties of studied steels. This work is focused on the laser marking of test pieces using a Yt- terbium fber laser. A dual phase steel (type JFE CA 1180) is studied. Process parameters are defned. Key words: marking, laser, advanced high-strength steels, AHSS, formability diagrams, mechanical properties. 1. INTRODUCTION The automotive sector is a prime consumer of stamped sheet met- al parts [1]. For some years now, the replacement of white-body parts stamped on conventional steels, with high-strength steels (for example dual phase steels) is continuous. In 1998, the car com- pany SAAB introduced for the frst time a hot stamped part, the four door reinforcements (Side Impact Beams). AHSS (Advanced High-Strength Steels) steels allow for thinner, lighter parts, with enhanced mechanical properties in the body structure [2]-[3]. These steels are a large family that includes so-called dual-phase, ferrit- ic-bainitic, martensitic, etc.[4] characterized by their increased me- chanical strength. Given the continuous and spreading use of these new steels, tra- ditional stamping companies must reconvert their know-how since high-strength sheets present a very different plastic behavior, which is why they require stamping dies design with more knowledge about sprinback and sheet plastic behavior [5]-[6]. Differences in behavior make these very diffcult materials to deform, with more signifcant elastic recovery that causes greater loads on both the stamping tools and press machines [7]. To facilitate the forming of these steels, the hot stamping tech- nique is used [8]-[9] and even in small-size batches, with a single forming tool [10] or using two of them to achieve better part ge- ometric accuracy [11]. Thus, industrial hot stamping systems im- prove in design and effectiveness with each new automotive pro- gram [12]. The practical way to know the behavior of sheet metal versus deformation during stamping is by obtaining the forming limit dia- grams [13]. This activity requires tensile testing [14] for the left part of the diagram where the deformations are of tension-compression type and Nakazima for the right part, where the deformations are tension-tension[15]. After obtaining the limit diagrams, they can be research article / artículo de investigación 1 8 | ISSN-L:0012-7361 | xxx | Vol. 96 nº 2 | March 2021 | Dyna Cod. 9869 | Materials Technology | 3312.08 Properties of materials Grid laser marking influence on high-strength steels tensile test behavior Daniel Martinez-Krahmer, Germán Abate, Alejandro Simoncelli, Nazareno Antunez, Vitaliy Mar- tynenko, Daniela Perez y Norberto López-de-Lacalle Daniel Martinez Krahmer 1,2 , Germán Abate 1,2 , Alejandro Simoncelli 1,2 , Nazareno Antunez 1,2 , Vitaliy Martynenko 1,2 , Daniela Perez 1,2 , Norberto López de Lacalle 3,4 1 Centro de Investigación y Desarrollo en Mecánica. Instituto Nacional de Tecnología Industrial (INTI). Avenida General Paz, 5445 - 1650 Miguelete, Provincia de Buenos Aires (Argentina). 2 Universidad Nacional de Lomas de Zamora. Facultad de Ingeniería. Juan XXIII y Camino de Cintura, 1832 - Buenos Aires (Argentina). 3 Centro de Fabricación Avanzada Aeronáutica. CFAA. Parque Tecnológico de Bizkaia, 202 - 48170 Zamudio, Bizkaia (España). 4 Universidad del Pais Vasco. UPV/EHU. Plaza Ingeniero Torres Quevedo, 1 - 48013 Bilbao (España). Grid laser marking influence on high-strength steels tensile test behavior Influencia del grillado láser sobre el comportamiento de probetas de tracción de un acero de alta resistencia To cite this article: MARTINEZ-KRAHMER, Daniel; ABATE, Germán; SIMONCELLI, Alejandro; ANTUNEZ, Nazareno; MARTYNENKO, Vitaliy; PEREZ, Daniela; LÓPEZ-DE-LACALLE, Norberto. GRID LASER MARKING INFLUENCE ON HIGH-STRENGTH STEELS TENSILE TEST BEHAVIOR. DYNA. Marzo 2021, vol. 96, no. 2, 6 pp. DOI: https://doi.org/10.6036/9869 DOI: https://doi.org/10.6036/9869 Received: 27/07/2020 • Reviewing: 29/07/2020 • Acepted: 25/09/2020 RESUMEN • Este artículo presenta un novedoso sistema vestible destinado a asistir la mo- vilidad de personas invidentes y débiles visuales en entornos urbanos mediante el simple uso de un teléfono inteligente y retroalimentación táctil. El sistema utiliza los datos de posicionamiento provistos por el sensor GPS del teléfono inteligente para localizar en tiempo real al usuario en el espacio y determinar las direcciones hacia un destino. Las instrucciones de navegación resultantes se codifican como patrones de vibración y se despliegan al usuario a través de una interfaz táctil integrada al zapato. Para validar la pertinencia del sistema propuesto, se realizaron dos experimentos. El primero involucró la participación de un grupo de 20 sujetos voluntarios visualmente sanos a los que se les pidió reconocer las instrucciones de navegación desplegadas mediante el dispositivo de estimulación podotáctil. Los resultados muestranaltas tasas de reconoci- miento. El segundo experimento consistió en conducir a dos sujetos voluntarios invidentes a lo largo de espacios públicos urbanos hacia destinos previamente establecidos. Los resultados fueron exitosos y sugieren que el sistema incrementa la navegación independiente y de forma segura de personas con discapacidad visual. A su vez, se muestra el potencial de los teléfonos inteligentes y los dispo- sitivos podotáctiles en las tecnologías de asistencia. • Palabras Clave: tecnologías de asistencia, localización GPS, movilidad de personas invidentes, estimulación podotáctil, interfaz vibrotáctil, sistema vestible.