Life extension and repair method of a vertical stainless steel bright annealed muffle tube

Abstract

The invention relates to a life extension and repair method for a vertical stainless steel strip bright annealing muffle tube. The life extension and repair method is characterized by comprising the following steps: 1) obtaining the using performances (a mathematical model) of a domestic muffle tube material through a tensile creep test and a lasting creep test and determining a material substitute for an imported muffle tube; 2) determining the repair length according to the defect type of the muffle tube and cutting off a section with defects; 3) performing repair welding of one section of the material substitute determined in the step 1) according to the total length requirement of the muffle tube and calculating the service life of the muffle tube after repair; and 4) performing the operations repeatedly according to the steps 2) and 3) when the defects occur again. Through the repair method provided by the invention, the domestic muffle tube material is successfully adopted to replace the imported material to repair the muffle tube and has the performances which are equivalent to those of the imported muffle tube material, the defects of an existing muffle tube repair technology and the problem of high production cost of the muffle tube material are solved, the up-and-down strength of the muffle tube after repair can basically achieve the consistency, the cost is low, and the service life of the whole muffle tube is simultaneously prolonged.

Description

technical field [0001] The invention relates to the field of cold-rolled stainless steel strip manufacturing, in particular to the technical field of a large-scale stainless steel strip vertical bright annealing muffle repair method. Background technique [0002] The large stainless steel strip bright annealing production line is the key process equipment for producing high surface grade stainless steel strip. The large bright annealing muffle tube is the key component of the stainless steel strip bright annealing furnace, which is used to ensure that the stainless steel strip is heated in a protective atmosphere and realizes recrystallization annealing , and finally get a stainless steel strip with a bright mirror surface. The muffle tube in the heating section of the bright annealing muffle furnace is filled with protective gas - 100% hydrogen, and 40 asymmetrically distributed burners fueled by liquefied petroleum gas or natural gas are used to heat the muffle tube outsid...

AI Technical Summary

Problems solved by technology

In this way, the repair cycle of the muffle tube is very short

[0007] 2) The material utilization rate is low. After the muffle tube has been repaired several times, due to the length limitation, it needs to be replaced as a whole

At this time, there are few or no defects in most areas of the muffle, which wastes most of the other muffle material

[0008] 3) The cost is high. Due to the short repair cycle of the muffle tube, production needs to be stopped for each repair, and there are repair costs

The cost of replacing the muffle tube is even higher, because the original muffle tube is imported

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