3 results about "Continuous cooling transformation" patented technology

The present application relates to a kind of X80 pipeline electric arc additive manufacturing method and system based on thermal-mechanical coupling regulation mechanism, the method includes: first, the continuous cooling transformation curve of X80 steel is determined to determine phase transition temperature interval;Thermal-mechanical coupling finite element model containing mobile heat source and mobile force source is constructed and calibrated;On this basis, process prediction model is established, and the mapping relationship between process parameter and temperature field, stress field is obtained;Optimization algorithm is used in simulation space to carry out reverse optimization, and the optimal thermal-mechanical coupling process parameter combination is obtained;Finally, in actual repair process, deposit layer temperature is monitored in real time by infrared temperature measurement, when temperature falls into phase transition temperature interval and approaches optimal impact intervention temperature, drive with welding ultrasonic impact device to execute mechanical impact.The present application can significantly reduce residual tensile stress and improve the degree of grain refinement.

The invention provides a carbide-free bainite steel continuous cooling carbide-free upper / lower bainite critical cooling speed determination method, which comprises the following steps: S1, carrying out phase change experiments at different cooling speeds, S2, obtaining phase change temperatures at different cooling speeds, S3, obtaining kinetic curves at different cooling speeds, S4, obtaining kinetic equations at different cooling speeds, and S5, determining the critical cooling speed of carbide-free bainite steel continuous cooling carbide-free upper / lower bainite. The method comprises the steps of S1, obtaining a kinetic equation, S2, obtaining a kinetic equation, S5, obtaining a kinetic curve under the kinetic equation, S6, S3 and S5, comparing the kinetic curves, S7, drawing a continuous cooling transformation curve capable of subdividing carbide-free upper / lower bainite, S8, determining cooling speeds of parts required by different cooling modes of the bainite steel component, and S9, determining the cooling mode of the bainite steel component. According to the method, phase change kinetic analysis is added, the carbide-free bainite is further subdivided into the carbide-free upper bainite and the carbide-free lower bainite, the research and development period of the bainite steel component is shortened, and the performance of the bainite steel is exerted to the maximum extent.

The invention relates to the technical field of metal material heat treatment, and provides a bearing steel grain uniformity optimization post-forging subsection cooling method, which comprises the following steps: carrying out a dynamic continuous cooling transformation test on a bearing steel sample through a thermal simulation test machine, and collecting a thermal expansion curve in a cooling process in the dynamic continuous cooling transformation test; the critical phase transition temperature of the bearing steel is determined by using a tangent method, so that the bearing steel is heated, forged and deformed. And cooling in a sectional manner, quickly cooling at a first-stage cooling rate, slowly cooling to a preset final temperature at a second-stage cooling rate, and naturally cooling to room temperature with air to obtain a finished bearing steel product. According to the method, the process parameters are cooled at multiple stages after bearing steel forging, the pearlite phase change process is accurately regulated and controlled, abnormal precipitation of secondary carbides is effectively inhibited, meanwhile, the hardness uniformity of the bearing steel is remarkably improved, the qualified mass production rate of the bearing steel is increased, the production cost is reduced, and key technical guarantee is provided for stable manufacturing of high-end large bearings.