7th IMRMPT

Abstract

Abstract information

English title:	Affectation in fatigue resistance in stainless steels with welded joints
Spanish title:	Afectaci�n en la resistencia a la fatiga en aceros inoxidables con juntas soldadas
English abstract:	Steel is very useful for many sectors nowadays, it is characterized as being hard and resistant, besides having great malleability. This material is in great demand in industries such as automotive, power generation, pharmaceutical, and food. They also make use of stainless steel, which has similar characteristics to those mentioned above with the addition that they are resistant to corrosion, in addition, they can be austenitic, martensitic, or ferritic. On the other hand, being such a demanded material, it is necessary to optimize the processes of transport, cutting, welding, and material saving, in order to generate advances in the metal-mechanical industry. Welding is a process that is carefully analyzed, the most appropriate method must be chosen for the material, looking for the best mechanical properties in critical test conditions. Therefore, to achieve these standards, the material was experimented with in controlled environments under international standards, the analysis was performed on 316L stainless steel with a welded joint, by the GMAW welding process, the main objective was to analyze the welded joint, and the changes that may occur with respect to the control material, which in this case was the initial material without the welded joint, the material was taken to critical loading conditions, with tensile tests that allowed to continue with the research delivering values of elastic limit. In this way, fatigue was performed at 4 stress levels associated with the yield stress for the analysis based on Basquin's model, it was observed how the structure changed when it was taken to the limit with this type of destructive test. In obtaining the specimens, the welding parameters for the working conditions initially proposed were sought, following the indications of the material manufacturer, a material metallurgically similar to the base plate was used as welding material. The GMAW welding process was carried out under the standards of the AWS D1.1 norm, with an automatic electromechanical system with constant displacement, on a horizontal surface, for the cutting of the specimens was guaranteed not to thermally affect the samples. Micrographs were taken with an optical microscope, for this process, it was required a treatment of samples in which they were roughened by hand with abrasive paper, then the material was attacked with reagent according to ASTM E407 standard, for proper visualization of the microstructural changes. Therefore, from the study of the micrographs results were obtained, comparing the formation of microstructures predicted by the Schaeffler diagram with the analysis performed on the images of the material. The analysis of the welded joint showed a notable difference with respect to the control material with each of the studies performed, but in the microstructures, changes in the material were noted that affected the corrosion resistance properties of the material used for this work. On the other hand, it was compared and a relationship was established between the equations obtained by the fatigue analysis model, with this relationship it can be set numerically how much the change between the welded material and the control material with the fatigue test.
Spanish abstract:	El acero es muy �til para muchos sectores hoy en d�a, se caracteriza por ser duro y resistente, adem�s de tener una gran maleabilidad. Este material es muy demandado en industrias como la automoci�n, la generaci�n de energ�a, la farmac�utica y la alimentaria. Tambi�n hacen uso del acero inoxidable, que tiene caracter�sticas similares a las mencionadas anteriormente con el a�adido de que son resistentes a la corrosi�n, adem�s, pueden ser austen�ticos, martens�ticos o ferr�ticos. Por otro lado, al ser un material tan demandado, es necesario optimizar los procesos de transporte, corte, soldadura y ahorro de material, para generar avances en la industria metalmec�nica. La soldadura es un proceso que se analiza cuidadosamente, se debe elegir el m�todo m�s adecuado para el material, buscando las mejores propiedades mec�nicas en condiciones cr�ticas de ensayo. Por lo tanto, para lograr estos est�ndares, se experiment� con el material en ambientes controlados bajo normas internacionales, el an�lisis se realiz� en acero inoxidable 316L con una uni�n soldada, por el proceso de soldadura GMAW, el objetivo principal fue analizar la uni�n soldada, y los cambios que pueden ocurrir con respecto al material de control, que en este caso fue el material inicial sin la uni�n soldada, el material fue llevado a condiciones cr�ticas de carga, con ensayos de tracci�n que permitieron continuar con la investigaci�n entregando valores de l�mite el�stico. De esta manera, se realiz� la fatiga a 4 niveles de tensi�n asociados al l�mite el�stico para el an�lisis basado en el modelo de Basquin, se observ� como cambiaba la estructura al ser llevada al l�mite con este tipo de ensayo destructivo. En la obtenci�n de las probetas se buscaron los par�metros de soldadura para las condiciones de trabajo propuestas inicialmente, siguiendo las indicaciones del fabricante del material, se utiliz� como material de soldadura un material metal�rgicamente similar a la placa base. El proceso de soldadura GMAW se realiz� bajo los est�ndares de la norma AWS D1.1, con un sistema electromec�nico autom�tico con desplazamiento constante, sobre una superficie horizontal, para el corte de las probetas se garantiz� no afectar t�rmicamente a las muestras. Las micrograf�as fueron tomadas con un microscopio �ptico, para este proceso, se requiri� de un tratamiento de las muestras en el cual fueron desbastadas a mano con papel abrasivo, posteriormente el material fue atacado con reactivo de acuerdo a la norma ASTM E407, para la correcta visualizaci�n de los cambios microestructurales. As�, a partir del estudio de las micrograf�as se obtuvieron resultados, comparando la formaci�n de microestructuras predicha por el diagrama de Schaeffler con el an�lisis realizado sobre las im�genes del material. El an�lisis de la uni�n soldada mostr� una diferencia notable respecto al material control con cada uno de los estudios realizados, pero en las microestructuras se observaron cambios en el material que afectaron a las propiedades de resistencia a la corrosi�n del material utilizado para este trabajo. Por otro lado, se compar� y se estableci� una relaci�n entre las ecuaciones obtenidas por el modelo de an�lisis de fatiga, con esta relaci�n se puede establecer num�ricamente cuanto es el cambio entre el material soldado y el material control con el ensayo de fatiga.
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Authors

Name	Institution	Email
Oscar Rodolfo Bohorquez Becerra	Universidad Industrial de Santander	obohorbe@correo.uis.edu.co
Alberto David Pertuz Comas	Universidad Industrial de Santander	apertuzc@uis.edu.co
Jhon Fredy Gonzalez Rodriguez	Universidad Industrial de Santander	jhonfredygonzalezrodriguez@gmail.com

Presentation

Room:	Principal Room
Date:	June 8, 2023
Hour:	17:20 - 17:40

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7^th IMRMPT
Seventh International Meeting for Researchers in Materials and Plasma Technology

Previous editions:

        1st IMRMPT 2011
        2nd IMRMPT 2013
        3rd IMRMPT 2015
        4th IMRMPT 2017
        5th IMRMPT 2019
        5+1 IMRMPT 2021

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