Thank you for participating in this discussion. You're correct—the fatigue appears to have initiated at the keyway, which acted as a stress concentrator, and this explanation seems quite reasonable. I also agree with your observation about the final fracture area near the 9:00 position, as I...
As I was initially impressed by the intergranular microstructure and shiny appearance of the fracture, I overlooked the presence of beach marks, and my interpretation was biased toward a brittle fracture mechanism. Fractography requires a trained eye and an unbiased review of the entire story...
Thank you for participating in this thread. I assume this is the most probable scenario. I was unable to observe any striations in the SEM images. Could you please elaborate on your observation? Are you referring to the lines with the darker background in the photo (Broken Shaft.jpg) that...
Thank you for the comment. When examined under light and tilted, the fracture surface exhibits a sparkling effect. This characteristic appears uncommon for fatigue-induced failures, as such fractures occasionally display such reflective properties. Additionally, the intergranular morphology of...
Thank you for participating in this thread. Similar grade in ASTM would be ASTM A276-420. The heat treatment was QT800 (950 0C -1050 0C quenched by forced air and tempered at 650-750 0C) and was tested according to ASTM A388-11.
Hello,
A broken pump shaft made of 1.4021 stainless steel failed at room temperature. The broken surface looks smooth and shiny, with some sparkles when tilted. Under the microscope, the cracks mostly followed the grain boundaries (intergranular fracture), which usually points to brittle...
