Welding method of super-thick steel casting

Abstract

The invention discloses a welding method of a super-thick steel casting. Process steps include S1, preparing a joint: an asymmetric X-type groove is adopted; S2, preheating: the front side and the reverse side are uniformly heated, the preheating temperature is set within the range of 150-160 DEG C, and the heating rate does not exceed 100 DEG C / h; S3, back welding: gas shielded welding backingis carried out on flux-cored welding wires for three layers, and fire warming is carried out to remove stress after each weld seam is welded; S4, reverse side air gouging: air gouging back chipping and carburized layer removal are carried out; S5, reverse side back welding: back welding is carried out by three layers after the temperature of the steel casting reaches a preheating temperature according to the method described in the step 2, and fire warming is performed on each weld seam to remove stress; S6, filling and cover surface welding: the front side and the reverse side are welded respectively by one welder simultaneously and symmetrically, and hammering is carried out layer by layer after each layer of weld beads of each weld seam is welded; and S7, 550 DEG C *2h heat treatment after stress removal is carried out immediately after the completion of welding. By means of the method, welding stress and welding deformation can be significantly reduced, and the probability of generating steel casting welding cracks is greatly reduced.

Description

technical field [0001] The invention belongs to the field of welding technology, in particular to a welding method for super-thick steel castings. Background technique [0002] Due to its flexible shape and size design, steel castings are usually used for stern tubes, rudder arms, rudder bearings, anchor lips and other parts of large ships. The size of the steel parts also increases accordingly. The maximum thickness of the welding position of the steel castings of the ultra-large ore ships and container ships is 150mm. For the welding of such ultra-thick steel castings, if the existing process is adopted, the following problems will occur: [0003] (1) The weldability is poor, and welding cracks are easily generated; [0004] (2) The amount of welding is large, the welding deformation is difficult to control, and the subsequent deformation is difficult to correct; [0005] (3) The welding stress is large, which affects the stable bearing capacity of the welded joint. Co...

AI Technical Summary

Problems solved by technology

[0003] (1) The weldability is poor, and welding cracks are easily generated;

[0004] (2) The amount of welding is large, the welding deformation is difficult to control, and the subsequent deformation is difficult to correct;

[0005] (3) The welding stress is large, which affects the stable bearing capacity of the welded joint

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