Welding method of airborne small rocket shell

Abstract

The invention discloses a welding method for an airborne small-sized rocket casing. The diameter of the airborne small-sized rocket casing is less than 200 mm, and the material is 30CrMnSiA low-alloy high-strength steel. The airborne small-sized rocket casing includes a front head casing and a front head casing. Processing of cylindrical rear joint shell, front head shell and cylindrical rear joint shell - processing of left section of butt welding specimen and right section of butt welding specimen - quenching and tempering - assembly, tack welding - shell Prefabricated parts and welding test pieces Prefabricated butt welds - weld seam radiographic inspection, repair welding, re-radiographic inspection and stress relief annealing. Welding after quenching and tempering of shell parts, the loss of weld strength is small, which can reach 95-100% of the strength of the base metal matrix (the tensile strength of the base metal matrix is ​​1080-1240MPa, and the tensile strength of the welded joint sample is 1026-1180MPa) ; The weld has good toughness and no cracks at a bending angle of 40°.

Description

technical field [0001] The invention relates to the technical field of solid rocket combustion chamber shell welding, in particular to a welding method for an airborne small rocket shell. Background technique [0002] With the rapid development of technologies such as drones and helicopters, more and more airborne defense products and environmental detection products powered by solid rockets are used, which are characterized by large quantities, high processing efficiency, and low manufacturing costs. [0003] Medium and large solid rocket motors are used as launch power devices for strategic missiles, tactical missiles, and military and civilian satellites. The product value of the solid rocket combustion chamber shell is high and the processing cycle is long. Its traditional butt welding adopts copper lining inner support to adjust the circle and support welding. After welding, after taking out the copper lining inner support, the operator drills into the shell and grinds ...

AI Technical Summary

Problems solved by technology

The traditional butt welding method of medium and large solid rocket combustion chamber shells is difficult to meet the new requirements of large number of airborne small rocket shells, high processing efficiency and low manufacturing cost

[0004] For small rocket shells with a diameter of less than 260mm and made of 30CrMnSiA low-alloy high-strength steel, class I butt welds are required, and the tensile strength of the welded joints shall not be less than 90% of the minimum tensile strength of the base metal matrix (σb welding ≥ 972MPa). Bending angle α≥40°, no depression is allowed on the back of the weld, and the weld reinforcement shall not exceed 0.3mm, and the total time for assembly, welding, disassembly, and grinding shall not exceed 20 minutes, and the traditional butt welding method cannot meet the requirements

[0005] The traditional rocket shell welding adopts argon shielded arc welding method. The disadvantage of this welding method is that the welding efficiency is low and the welding deformation is large.

If the processing efficiency is to be improved, the parts are welded after quenching + tempering, and the weld strength loss is large, generally less than 70-80% of the matrix strength, which cannot meet the performance requirements of not less than 90% of the matrix strength

In addition, the shell is subjected to quenching + tempering heat treatment after welding, and the process is long. It needs to go through welding, flaw detection, annealing, quenching, tempering, shape correction, machining and other processes, which is not suitable for the mass production of small rocket shells.

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