Welding method for connecting ferrite stainless steel steel-strip with thickness of 3-6 mm

Abstract

The invention belongs to the technical field of ferrite stainless steel steel-strip connecting, and particularly discloses a welding method for connecting ferrite stainless steel steel-strip with a thickness of 3-6 mm. The welding method comprises the following steps: shearing two steel strip heads to be welded, pressing a steel strip, and enabling the two steel strip heads to align to form a seam with a trapezoidal cross section; filling nickel-based welding material into the welding seam, and using a welding wire with the diameter of 1.2mm to weld along one end of the welding seam; and carrying out stress-relief annealing on the welding seam after the welding is completed. The welding method adopts a laser welding process to connect the ferrite stainless steel steel-strip, the welding seam is flat, free of the defects of welding pores, welding flash and the like, degree of welding seam heat effect on structure grain coarsening degree is controlled to be lower than level 2, annealing treatment is carried out on the welding seam, welding residual stress on the welding seam is eliminated, and joint mechanical properties of the welding seam is improved.

Description

technical field [0001] The invention belongs to the technical field of connecting ferritic stainless steel strips, in particular to a welding method for connecting ferritic stainless steel strips with a thickness of 3-6mm. Background technique [0002] Compared with austenitic stainless steel, ferritic stainless steel has a narrow range of welding parameters, is more sensitive to heat input, and the grains of the structure are easy to coarsen. If the welding process is not properly controlled, it is easy to cause coarse-grain embrittlement of the welded joint, which in turn leads to The comprehensive mechanical properties are reduced. When the ferritic stainless steel strip passes through the annealing and pickling line, in order to ensure the continuous operation of the production line, the head and tail of the uncoiled steel strip should be welded together. The main welding method is lap resistance welding or melting electrode argon arc welding. [0003] In order to impro...

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Problems solved by technology

[0003] In order to improve production efficiency, well-known iron and steel enterprises at home and abroad have invested in the construction of cold tandem rolling mill production lines. During the operation of the steel strip, the welded joints are subjected to complex forces and are affected by tension, bending forces and rolling forces. High performance requirements are put forward, especially in the rolling process, the steel strip welds are subject to great rolling tension. If the mechanical properties of the joint welds are insufficient, the strip is prone to breakage, making maintenance difficult, reducing product quality and Production efficiency, but the performance of welded joints of steel strips welded by lap resistance welding or argon arc welding can no longer meet the requirements of the operating conditions of the cold tandem rolling mill.

In the production of ferritic stainless steel cold continuous rolling plate, due to improper control of the laser welding process of steel strip connection, the phenomenon of strip breakage occurs from time to time, resulting in production interruption. Among them, the weld seam of ferritic stainless steel with a thickness of 3-6mm is the easiest Breakage occurs, which seriously affects the normal production of the unit

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