The following is the process of quenching and tempering heat treatment for the blank of cylinder forgings. Compared with the original rough machining quality, the adjustment of the blank quality saves the rough machining production process of forgings, that is, the cross workshop transportation, rough machining and other production cycles are shortened, the rough machining alignment process is saved, the forging is processed to the finish machining size, the labor consumption and mechanical equipment occupation of cold machining are greatly saved, and the production progress of the cold machining process is accelerated; The forging and heat treatment of hydrogenation cylinder section are carried out in the same workshop, which is convenient for production organization and coordination and effectively improves productivity.
Production process:
Steelmaking - forging - post fracture heat treatment - rough machining - ultrasonic flaw detection - welding thermal buffer block - performance heat treatment - performance inspection - such as blank warehouse after processing and flaw detection.
Quenching and Tempering Process of Barrel Forging Blank
Improvement process: After the forging process is completed, heat treatment is required after forging. Due to the progress of smelting technology, the hydrogen content and impurity elements in steel have been effectively controlled. Therefore, the main purpose of post forging heat treatment is to adjust and refine the grain, so as to make organizational preparation for performance heat treatment and ultrasonic flaw detection after subsequent rough machining.
Due to the large size of forgings, it is easy to produce grain thickness and mixed crystals in the forging process. Coarse crystals and mixed crystals will reduce the strength, plasticity and impact toughness, especially the impact toughness. To prevent the above problems, the annealing process is used for heat treatment.
After heat treatment of forgings, heat buffer blocks shall be welded according to technical conditions, and then performance heat treatment shall be carried out for forgings. Compared with the rough machining+quality regulation process of cylinder forgings, we adopt the method of moving up and down when the forgings are water-cooled. This is mainly due to the formation of thick oxide skin after high temperature forging and heat treatment after forging. After entering the water, due to the high temperature, a layer of steam bubbles forms on the surface of the forging, and the rough oxide skin hinders the rise and overflow of the bubbles, which is equivalent to a layer of insulation layer on the surface of the forging blank.
Therefore, in the cooling stage of blank quality regulation, we took the measure of moving the forging up and down immediately after the water entering the forging, so as to make the bubbles overflow quickly, so as to achieve the purpose of rapid cooling of the forging. At the same time, adjust the performance heat treatment process.