Process for assembling and welding ultralong hollow shafting auger flight

Abstract

The invention provides an assembly welding process for an ultra-long hollow shaft helical blade, which mainly comprises two assembly welding processes, namely the pre-heating welding of the helical blade on the ultra-long hollow shaft and the overlaying welding of the antiwear layer on the helical blade and a process of the overall annealing of overlaying welding. In the assembly welding processes, the small-pore tubing negative pressure siphoning type air supply combustion-supporting gas heating is utilized to solve the problem of preheating the high-carbon equivalent material; by evaluating the welding processes of a plurality of overlaying welding materials, the welding method, the welding material and the welding condition are finally determined; and the result meets the hardness(HRC54 to 06) of the antiwear layer required in the design, which is the necessary hardness obtained after annealing, and solves the new welding stress problem generated due to the overlaying welding after annealing. Moreover, the process has the advantages of easily obtained material, simple preparation, time conservation and labor conservation, and low cost.

Description

technical field [0001] The invention belongs to the field of welding technology, and in particular relates to an assembly and welding process of an ultra-long hollow shaft helical blade. Background technique [0002] The blade-type screw shaft configured on the shield machine is a hollow super-long-body welded structural part. The weldability of this type of structural part is generally determined from the carbon equivalent of the base metal, the restraint degree of the structure, and the hydrogen content of the deposited metal. define and judge. The difficulty of manufacturing structural parts often depends on the symmetry and rigidity of the structure, the degree of automation of applicable welding methods, labor intensity and working environment and other factors. [0003] The outstanding issues for the production of this type of structural parts are: [0004] The selected base metal has high strength, in other words, poor weldability, preheating before welding is the m...

AI Technical Summary

Problems solved by technology

[0004] The selected base metal has high strength, in other words poor weldability, preheating before welding is the most prominent contradiction, asymmetric structure, poor rigidity, not suitable for welding tooling, high production cost, large deformation after stress relief

[0005] Due to the high threshold of the industry, outstanding technological added value, and complicated manufacturing process, only a few professional enterprises such as Herrenknecht and Wirth in Germany, Robbins in the United States, Mitsubishi in Japan, and Ishikawa Island can produce in the world, and the price of each machine is as high as 4 million to 7 million US dollars, which seriously restricts the production enterprises in our country