Pipeline Multi-Pass Welding Without Grinding at Arc Starts
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Solution Overview
Problem
The existing pipeline welding technologies require grinding of the arc starting zone and points, which increases costs, poses health risks due to metal dust, reduces efficiency, and is prone to human error affecting welding quality.
Innovation Solution
An all-position multi-layer multi-pass grinding-free welding method that uses non-consumable electrode welding for initial heating and consumable electrode welding for subsequent passes, controlling the arc starting stage by stage without grinding, to improve welding efficiency and quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If grinding is performed on arc starting zones and points, then welding quality is improved, but productivity is reduced
Solution Approach 1:
The non-consumable electrode welding is performed as a preliminary action before the consumable electrode welding. This preliminary welding creates a smooth arc starting position and cleans oxides in advance, eliminating the need for subsequent grinding operations while maintaining high welding quality
Solution Approach 2:
The harmful grinding operation is extracted and removed from the welding process. The patent replaces the grinding step with a preliminary non-consumable electrode welding that achieves the same quality improvement without the negative effects of metal dust and time consumption
2Manufacturing precision
If grinding equipment and personnel are equipped, then welding quality is improved, but device complexity is increased
Solution Approach 1:
The non-consumable electrode welding torch serves multiple functions: it performs the primary welding function and simultaneously prepares the arc starting position by smoothing and oxide cleaning. This multi-functionality eliminates the need for separate grinding equipment and personnel
Solution Approach 2:
The grinding equipment and personnel are extracted and removed from the welding system. The patent achieves quality improvement through the welding process itself rather than through separate preparation equipment
3Manufacturing precision
If grinding is performed, then welding quality is improved, but loss of time is increased
Solution Approach 1:
The arc starting position preparation is performed as a preliminary action during the non-consumable electrode welding phase, before the main consumable electrode welding begins. This eliminates the need for separate time-consuming grinding operations later in the process
Solution Approach 2:
The welding process maintains continuity by integrating the arc starting position preparation into the welding itself. The non-consumable electrode welding continuously prepares the surface while welding, eliminating idle time for separate grinding operations
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enhances welding efficiency and quality by eliminating the need for grinding, improving the working environment, and reducing labor intensity while ensuring smooth arc starting positions and effective oxide cleaning.
Implementation Method 1
by the non-consumable electrode welding, which can heat the arc starting position of a workpiece
Implementation Method 2
Due to the high temperature of the arc starting zone of the workpiece when the welding wire is filled by the consumable electrode welding, a molten pool may not be cooled down rapidly, which can be fully spread out
Data Source
AI summary
A grinding-free welding method for full-position multi-layer multi-pass welding of a pipeline, includes the following steps: preparing before welding, positioning and aligning, and performing root welding; respectively carrying out clockwise and anticlockwise arc welding on a thermal welding layer, filling layers and cover surface layers, controlling arcing in a segmented mode in a preset lap joint area by means of non-consumable electrode welding and consumable electrode welding, and then carrying out subsequent welding by means of consumable electrode welding. The method controls arcing in a segmented mode by means of non-consumable electrode welding and consumable electrode welding, and carries out subsequent welding by means of consumable electrode welding. The non-consumable electrode welding process is free of welding wire filling and a workpiece arcing area can be heated, then welding wire filling is carried out by means of consumable electrode welding.