Análisis de estabilidad microestructural durante fluencia lenta en acero 1.25Cr0.5Mo envejecido en servicio y sometido a PWHT
Fecha
2014-07-20
Autores
Heredia Guerra, Andy
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Editor
Universidad Central "Marta Abreu" de Las Villas
Resumen
En la actualidad un grupo importante de componentes en la industria están sometidos a condiciones de trabajo que combinan la acción de cargas mecánicas con temperaturas entre 450 oC y 600 oC. Bajo estas condiciones de trabajo dichos componentes sufren el fenómeno de degradación conocido como fluencia lenta. Este fenómeno depende de la estabilidad microestructural del acero empleado,
por lo que el estudio del comportamiento de la microestructura durante la fluencia lenta es de gran interés. En este sentido en el presente trabajo se plantea el objetivo de analizar la evolución microestructural en probetas sometidas a ensayo de fluencia lenta. Las probetas se fabricaron con acero 1.25 Cr0.5Mo expuesto al servicio por más de 20 años en una tubería de conducción de vapor a 480 oC, así como sometidas a tratamiento térmico similar al empleado para la reparación por
soldadura. Como resultado del trabajo se promueven procedimientos para la determinación de los parámetros microestructurales y se evalúa el comportamiento de los parámetros de entrada: número de partículas por unidad de área y tamaño medio de las partículas; así como de los parámetros de salida: número de partículas por unidad de volumen, fracción de volumen de partículas y
distancia entre partículas; llegándose a obtener modelos estadísticos que permiten describir la estabilidad microestructural.
At the present time an important group of components in the industry are subdued to working conditions that combine the action of mechanical loads with temperatures between 450 oC and 600 oC. Under these working conditions said component they suffer the phenomenon of degradation known as slow flow (creep). This phenomenon depends on micro-structural stability of the steel used, which is why the study of the behavior of the microstructure during the slow flow becomes of great interest. In this sense in the present work, microestructural in test tubes subdued proposes the objective to analyze evolution to essay of creep. The test tubes manufactured themselves with steel 1, 25 Cr0.5Mo once the service for over 20 years in a steam-driven conduit was exposed to 480 oC manufactured the test tubes themselves with steel, as well as submitted to similar heat treatment to the employee for the repair for welding. As a result of the work promote procedures for the determination of the microstructural parameters and evaluate the behavior of the inbound parameters: number of particles by unit of area and mid-size of the particles; as well as of the parameters of exit: number of particles for volume unit, fraction of volume of particles, and distance between particles; taking place the obtaining of statistical models that allow describing microstructural stability.
At the present time an important group of components in the industry are subdued to working conditions that combine the action of mechanical loads with temperatures between 450 oC and 600 oC. Under these working conditions said component they suffer the phenomenon of degradation known as slow flow (creep). This phenomenon depends on micro-structural stability of the steel used, which is why the study of the behavior of the microstructure during the slow flow becomes of great interest. In this sense in the present work, microestructural in test tubes subdued proposes the objective to analyze evolution to essay of creep. The test tubes manufactured themselves with steel 1, 25 Cr0.5Mo once the service for over 20 years in a steam-driven conduit was exposed to 480 oC manufactured the test tubes themselves with steel, as well as submitted to similar heat treatment to the employee for the repair for welding. As a result of the work promote procedures for the determination of the microstructural parameters and evaluate the behavior of the inbound parameters: number of particles by unit of area and mid-size of the particles; as well as of the parameters of exit: number of particles for volume unit, fraction of volume of particles, and distance between particles; taking place the obtaining of statistical models that allow describing microstructural stability.
Descripción
Palabras clave
Acero 1.25Cr0.5Mo Envejecido, Fluencia Lenta, Industria, Estabilidad Microestructural, Probetas, Tratamiento Térmico