The effects of aging process after solution heat treatment on drilling machinability of corrax steel

As a maraging steel, Corrax, is used in many engineering applications in the manufacturing, aerospace, and medical industries thanks to its properties such as high strength, hardness and corrosion resistance. However, these high specifications can cause some issues for manufacturing operations such as forging, machining, grinding. In addition to that, using heat treatment applications changes materials' mechanical specifications, affecting the material's behavior during machining. Therefore, it is important to characterize the influences of different heat treatment conditions on the material's property and behavior. In this study, the effects of heat treatment process on the mechanical properties, drilling machinability and corrosion resistance of Corrax steel were experimentally investigated with the samples of solution heat treated and aged at 400 °C, 525 °C, 600 °C, and 700 °C. The machinability was evaluated based on thrust force, chip morphology, hole quality, and tool wear. The results showed that the thrust force, torque and hole quality depend on feed rate, cutting speed, and mechanical properties affected by aging treatment. The highest hardness (47.4 HRC), ultimate tensile strength (1720 MPa), maximum elongation (33%), and toughness (198 jm-3) were obtained for the sample which aged at 525 °C for four hours, consequently the highest cutting force and surface roughness results were measured for this sample. Better hole surface quality and less burr formation were observed in the samples aged at 600 °C and 700 °C, and not-aged. On the other hand, while the highest value of corrosion potential were measured in the sample aged at 400 °C, the lowest corrosion potential value were measured in the sample aged at 700 °C. Graphical abstract: [Figure not available: see fulltext.].