7 results about "Continuous cooling transformation" patented technology

The application discloses a method for online regulation and control of surface crack inhibition based on casting blank structure, which comprises the following steps: establishing a continuous cooling transformation database of steel; and establishing a casting blank structure regulation and control system from the horizontal section of continuous casting to the furnace mouth, and regulating and controlling the casting blank structure based on cooling process control. The application has the beneficial effects that: the surface layer structure of the casting blank is adjusted through cooling process control at the horizontal section of the continuous casting, on the one hand, the continuous cooling transformation database of the steel is established to provide accurate data for the structure regulation and control based on the temperature system; on the other hand, the starting temperature and the ending temperature are called in real time from the established continuous cooling transformation database of the steel according to the continuous casting steel grade, and the cooling speed in the regulation and control process is dynamically calculated according to the steel structure requirement and the real-time temperature of the casting blank, so that the regulation and control for different steel grades and target structures are more accurate; and the surface structure of the casting blank is regulated and controlled, and automatic control is completely adopted, so that the advantages of accuracy, high efficiency and convenience are achieved.

Provided in the present disclosure are a method and apparatus for predicting microstructural property parameters of a rolled bar. The corresponding method comprises: acquiring the cooling rate of a rolled bar, wherein the diameter of the rolled bar is less than a preset value; and on the basis of the cooling rate, and a continuous cooling transformation model of a material corresponding to the rolled bar, predicting microstructural property parameters of the rolled bar. Different from an existing method for predicting microstructural property parameters of a rolled bar, the present disclosure predicts a microstructural transformation result of a bar by using an actual measurement curve together with a temperature transformation curve of a material, no accurate temperature calculation curve and phase change model are required during the prediction, and an obtained result can better reflect the actual situation on a field, and is more accurate and practical.

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 provides a method and a system for establishing a continuous cooling phase transition temperature model of steel. The method comprises the following steps: through a continuous cooling transformation experiment, acquiring swelling capacity, temperature and time data of a steel sample at two minimum cooling speeds; respectively drawing expansion curves of the steel sample at two minimum cooling speeds according to the acquired expansion amount, temperature and time data, and determining two phase change starting points and two phase change ending points at the two minimum cooling speeds according to the expansion curves; determining an intersection point of the two straight lines according to the two determined phase change starting points and the two determined phase change ending points; presetting an initial cooling point, determining a cooling speed of a third experiment according to the determined intersection point, and performing the third experiment to obtain a phase change starting point and a phase change ending point of the third experiment; and establishing a mathematical model of phase change temperature and time by using the three groups of phase change starting points and the three groups of phase change ending points. According to the method, the continuous cooling phase transition temperature of the steel can be predicted with the least number of experiments at high precision.

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.

The invention provides a method and device for predicting structure property parameters of a rolled bar. The corresponding method comprises the steps that the cooling rate of the rolled bar is obtained; wherein the diameter of the rolled bar is smaller than a preset value; and predicting structure property parameters of the rolled bar according to the cooling rate and the continuous cooling transformation model of the corresponding material of the rolled bar. Compared with an existing method for predicting the structure property parameters of the rolled bar, the method has the advantages that the actually measured curve is matched with the temperature transformation curve of the material, the structure transformation result of the bar is calculated, an accurate temperature calculation curve and a phase change model are not needed in the calculation process, and the obtained result can better reflect the actual situation of the site and is more accurate and practical.