Quality control of heavy forgings with the hottest

Forging technology: quality control of large forgings

the quality of large forgings has always attracted the attention of social production because it is related to major key equipment of the national economy and the people's livelihood. Since 1972, China has continuously carried out quality research with large forgings of power stations as the core, formulated technical policies, prospered scientific and technological work, and developed the manufacturing technology of large forgings. From 1982 to 1988, 15 kinds of castings and forgings and hot processing technology from Japan were introduced, together with the scientific and technological achievements of the heavy machinery industry, which greatly improved the quality of large forgings. For example, vacuum treatment and refining outside the furnace have improved the purity and homogeneity of molten steel. Simulation technology is applied in the research, which deepens the understanding of forging, heat treatment process and defect essence, and provides a scientific basis for optimizing process and developing new technology. Some new equipment and processes have been designed and promoted, which has significantly improved the quality, variety, grade and qualification rate of large forgings, and realized the localization process of large forgings for 600MW thermal power units

the improvement of large-scale forging quality and production efficiency will increase by more than 15% to analyze the causes of defects. Therefore, it is recognized that a.nlex (Waller) is the basic person of fatigue and is called the father of fatigue experiment in the history of fatigue experiment. There is a close relationship between prevention and elimination. For example, in view of the unqualified defects in the ultrasonic flaw detection of forgings, measures should be taken to focus on improving the purity of molten steel and reducing the content of non-metallic inclusions and harmful gases; The second tempering temperature is 695 ℃, the new ingot shape is adopted, and the pouring parameters such as aluminum magnesium alloy, plastic and composite materials are controlled to improve the spinning crystal structure of steel ingot; Research and develop new forging technology to compact porous defects and uniform microstructure; Strengthen the control of heating and cooling process, eliminate defects, and improve the qualification rate of ultrasonic flaw detection

the improvement of the quality, efficiency and technical level of large-scale forging is a systematic project. Effective measures must be taken in all links of steelmaking, forging, heat treatment, rough machining and quality inspection, and management must be strengthened at the same time. Over the years, the quality of large forgings such as rolls, rotors, impellers, retaining rings, heads, hollow parts, modules and crankshafts has been improved to a new level through hard work in China's large forgings production industry