Steam feeding insert pipe and cylinder body butting and fixing process for steam turbine

Abstract

The invention provides a steam feeding insert pipe and cylinder body butting and fixing process for a steam turbine. The process comprises the following steps of: welding, namely selecting an E6015-B3(R407) welding bar as a welding material for filling a welding seam between a steam feeding insert pipe (1Cr9Mo1VNbN) and a cylinder body (ZG15Cr2Mo1) and carrying out welding; carrying out thermal treatment, namely carrying out after-welding thermal treatment on the welding seam which is formed in welding; processing the quality of a joint; and removing the filling welding material which is exposed out of the joint. Thus, by accurately selecting the welding material and strictly controlling the technological parameters, the occurrence probability of cracking of the welding seam and welding defects is reduced, and the welding reliability of a butted position of the steam feeding insert pipe and the cylinder body is improved.

Description

technical field [0001] The invention relates to the field of dissimilar steel butt joint processing technology, in particular to a process for butt joint and fixation of dissimilar steel for high and medium pressure steam inlet insert pipes and cylinder blocks of supercritical steam turbines. Background technique [0002] For steam turbines such as supercritical, one-time intermediate reheating, single-shaft, three-cylinder four-exhaust steam, and condensing steam turbines, the high and medium pressure steam inlet inserts are forged with 1Cr9Mo1vNbN material (equivalent to SA186-F91) The reducing pipe, the connecting seat of the high and medium pressure outer cylinder is a casting made of ZG15Cr2Mo1 integrally cast with the cylinder body, and the big head of the reducing pipe and the connecting seat are butt-jointed by welding filled with nickel-based welding materials. Cracks are prone to occur, and the butt fixing effect of the butt joint between the steam turbine intake p...

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Problems solved by technology

[0002] For steam turbines such as supercritical, one-time intermediate reheating, single-shaft, three-cylinder four-exhaust steam, and condensing steam turbines, the high and medium pressure steam inlet inserts are forged with 1Cr9Mo1vNbN material (equivalent to SA186-F91) The reducing pipe, the connecting seat of the high and medium pressure outer cylinder is a casting made of ZG15Cr2Mo1 integrally cast with the cylinder body, and the big head of the reducing pipe and the connecting seat are butt-jointed by welding filled with nickel-based welding materials. Cracks are prone to occur, and the butt fixing effect of the butt joint between the steam turbine intake pipe and the cylinder block is poor

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