THE CONTENT, SHAPE AND DISTRIBUTION OF NONMETALLIC INCLUSIONS HAVE GREAT INFLUENCE ON THE END PRODUCT RATE AND MECHANICAL PROPERTIES OF LARGE FORGINGS. IN THIS PAPER, BY USING 1220℃.HIGH TEMPERATURE MOIRE TECHNIQUE COMBINED WITH PHYSICAL MODELING METHOD, VARIOUS SHAPING PROCESSES AND COGGING-SHAPING COMBINED PROCESSES HAVE BEEN SYSTEMATICALLY INVESTIGATED WITH REGARD TO THE INTERNAL CAVITY CLOSING AND INCLUSIONS SHAPE CONTROL PROBLEMS IN THE HEAVY DISC PRODUCTION OF OUR COUNTRY.
IN THE HIGH TEMPERATURE PHYSICAL MODELING, STEEL 45# IS SELECTED AS MODELING MATERIAL AND THE EXPERIMENTS ARE CARRIED OUT AT 1220℃. FIRST, THE CHANGE OF INCLUSIONS SHAPE AND DISTRIBUTION AFTER DIFFERENT SHAPING PROCESSES HAS BEEN SYSTEMATICALLY STUDIED AND THE OPTIMUM FINAL SHAPING PROCESSES HAS BEEN SYSTEMATICALLY STUDIED AND THE OPTIMUM FIND SHAPING PROCESS WAS OBTAINED. BY USING THE MOIVE MODELING METHOD AT 1220℃ HIGH TEMPERATURE AND AT ROOM TEMPERATURE, THE METAL FLOWING, DISTRIBUTION OF INTERNAL STRAIN, THE EFFECT OF DIFFERENT SHAPING PROCESSES AND TEMPERATURE GRADIENT ON THE INCLUSIONS SHAPE AND ITS DISTRIBUTION HAVE BEEN OBTAINED. THEN, THE COMBINED COGGING-SHAPING PROCESSES HAVE BEEN INVESTIGATED TO OBSERVE ITS SYNTHETICAL INFLUENCE ON INCLUSIONS SHAPE. THE NEW TECHNOLOGY, WHICH ELIMINATES THE UPSETTING PROCESS AND USES DIRECT ELONGATION PROCESS COMBINED WITH CONVEX SHAPING PROCESS, AIMING AT GETTING SPHERIC INCLUSIONS IN THE FINISHED FORGINGS, WAS SUGGESTED. THE RATIONAL COMBINATION OF ELONGATION RATIO AND UPSETTING RATIO OF SHAPING PROCESS HAS BEEN INVESTIGATED, AND THE OPTIMUM FORGING TECHNOLOGY OF LARGE HEAVY DISC FORGINGS WITH LARGE ELONGATION RATIO AND SMALL SHAPING UPSETTING RATIO HAS BEEN OBTAINED.
BASED ON THE EXPERIMENTAL RESULTS, SOME SUGGESTIONS FOR IMPROVING THE FORGING TECHNOLOGY OF SEVERAL LARGE DISK FORGING PRODUCTS HAVE BEEN MADE. THE RESEARCH RESULT OF THIS THESIS WILL BE OF GREAT IMPORTANCE FOR IMPROVING THE INTERNAL QUALITY OF HEAVY DISC FORGINGS AND REDUCING THE REJECT RATE.
KEYWORDS: INCLUSION, LARGE FORGINGS, HEAVY DISK, FORGING PROCESS, PHYSICAL MODELING, MOIRE METHOD