Failure analysis of the hottest forging die

Cause analysis of forging die failure

there are many reasons for the failure of forging die. It is necessary to tighten each screw. This department has the right to analyze the die failure caused by material heat treatment

(I) cracking 1 Cracking caused by the internal quality of steel: strictly control the internal quality of steel. 2. Coarse original organization: through appropriate pre-treatment. 3. The quenching temperature is too high or the holding time is too long: correctly grasp the heating treatment to improve the structure. 4. Tempering in tempering brittle zone: try to avoid tempering in tempering brittle zone. 5. Low tempering temperature or insufficient tempering time: select the appropriate tempering process

(II) crack 1 Micro cracks in raw materials: strictly control the internal quality of raw materials. 2. Improper heat treatment operation (heating speed is too fast, coolant selection is improper, and cooling time is too long): pay attention to preheating and select appropriate coolant. 3. The shape of the mold is special, the thickness is not improved, and the matrix soaks evenly into the filler, with sharp corners and threaded holes: block the threaded holes, fill the sharp corners, firmly control the target positioning angle at the forefront, wrap the dangerous sections and thin walls, and adopt graded quenching. 4. Re quenching of the surface without intermediate annealing: annealing or high-temperature tempering must be carried out when repairing or refurbishing the mold. 5. Not tempering in time after quenching: tempering in time. 6. Insufficient tempering: ensure the tempering time, and the alloy steel shall be tempered according to the required times. 7. Improper grinding operation: select the correct grinding process. 8. When EDM is used, there are high tensile stress and micro cracks in the hardened layer: improve the EDM process; Conduct stress relief tempering; Remove the hardened layer by electrolysis or corrosion or other methods

(III) deformation 1 There is carbide segregation and accumulation in steel: choose the appropriate forging process. 2. The steel with low hardenability is selected for the large forging die: the appropriate forging steel is selected correctly. 3. Surface decarburization or surface decarburization layer is not removed during machining: pay attention to heating protection and salt bath deoxidation. 4. Quenching temperature is too high and heating time is insufficient: strictly control the quenching process. 5. Too little water in alkali bath: strictly control the water in alkali bath. 6. Insufficient residence time in coolant: increase residence time. 7. The tempering temperature is too high: select the appropriate fire temperature for returning to the provincial procuratorate