On December 5th, it was learned that Process Compilation Principle for Multidirectional Precise Die Forgings of Valves (JB/T 13274-2017) and General Technical Specification for Multidirectional Precise Die Forgings of Valves (JB/T 13275-2017) were officially approved by the Ministry of Industry and Information for publication. The implementation date is April 1st, 2018.
As standards formulated by our country through independent research and development without corresponding international or foreign standards, and reaching the domestic advanced technical level, these standards solve the shortage problem of processing technology standards for the multidirectional die forgings of valves in the Chinese valve industry. In the major national special science and technology project Top-Grade Numerically-Controlled Machine Tool and Basic Manufacturing Equipment Project in 2012, ‘Common Manufacturing Technology Research of Large-scale Multidirectional Die Forgings’ was listed as a task for research. These two standards were formed on the basis of this research task and constitute its important research achievements. The research, formulation, publication and implementation of these standards will energetically promote the supporting design and production capacity of domestic high-end valve and valve body die forgings, further promote the stability and normalization of the high-end product production and development of multidirectional valve and valve body die forgings, lay a solid foundation for the industrial development of domestic multidirectional valve and valve body die forgings, and play a role in positively promoting the realization energy conservation, material conservation and consumption reduction in China’s forging industry.
The main contents of these two standards stipulate the process compilation standards, process parameter confirmation, blank preparation and heating, die and forging equipment selection of multidirectional valve and valve body die forgings, technical requirements, test methods, inspection rules, marks, labels and accompanying documents, packaging, transportation and storage conditions, etc. of die forgings. The multidirectional valve and valve body die forging process is the forging process for shaping blanks either in several directions or in order, including dummying for blanks while compounding dies and the hole punching and extrusion forming of many terrace dies. In forging, blanks flow in a pressure stress state and their materials have strong plastic deformation, uniform deformation, dense organization and good performance consistency, forming continuous and integrated metal streamlines which are especially suitable for valve body forging with complex shapes, inner bores and high accuracy requirements. This process can save hours of machining work for the raw materials of die forgings and follow-up machines, thus promoting productivity, saving materials and reducing energy consumption. Integrated with the merits of extrusion and die forging, this process is regarded as the current most optimal process method of high-end valve and valve body forging.