Intermediate Tubular Workpiece for Non-Rotatable Pipe Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid state welding methods are limited in joining metal workpieces where rotation of the workpieces is not feasible, such as when joining long segments of pipe for pipeline laying, as they require rotation to achieve a strong bond.
Innovation Solution
A system and method that utilize an intermediate clamp and induction coils to heat and rotate an intermediate tubular workpiece positioned between two workpieces, allowing for plastic deformation and bonding without the need for workpiece rotation, using a non-oxidizing atmosphere to create a strong, uniform bond.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional solid state welding method is used to join metal workpieces, then a strong bond is achieved through rotation and shearing action, but the method is not applicable when rotation of workpieces is not feasible (e.g., long pipeline segments)
Solution Approach 1:
The patent introduces an intermediate tubular workpiece as a mediator between two workpieces to be joined. This intermediate piece can be rotated independently while the main workpieces remain stationary, enabling the welding process for non-rotatable applications. The intermediate workpiece transfers the rotational shearing action to the joint interface without requiring the primary workpieces to rotate.
2Temperature
If multiple segmented induction coils are used for larger diameter pipes, then sufficient heating is achieved, but the system complexity increases
Solution Approach 1:
The patent divides the induction heating system into multiple segmented coils that can be independently controlled. Each coil heats a specific zone of the workpiece, allowing precise temperature control at different locations. This segmentation enables effective heating of large diameter pipes while maintaining manageable system complexity through modular coil units.
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
Enables effective bonding of metal workpieces without the need for workpiece rotation, resulting in a strong, uniformly fine-grained microstructure and eliminating the need for filler materials or post-weld stress relief, suitable for joining pipes with varying diameters and wall thicknesses.
Implementation Method 1
The workpieces W1, W2 are heated by passing current through the induction coil that is located in a gap 18 between the respective ends 14A, 14B
Implementation Method 2
one or both of the workpieces is rotated, subjecting the material in the heated layers to shear stresses
Implementation Method 3
the contact surfaces of the workpieces tend to adhere to each other when they engage
Implementation Method 4
the material in the heated layers at the ends of the workpieces are pushed together axially, and simultaneously, one or both of the workpieces is rotated
Data Source
AI summary
A method of joining metal workpieces together. The method includes an intermediate metal workpiece between first and second metal workpieces to define gaps therebetween, and positioning induction coils in the gaps. The induction coils are energized, to heat hot portions in the first and second workpieces and intermediate hot portions in the intermediate workpiece in a non-oxidizing atmosphere to at least a hot working temperature. The induction coils are removed from the gaps, and the intermediate workpiece is rotated about an axis thereof. Contact surfaces on the first and second workpieces are pressed against the intermediate contact surfaces of the intermediate workpiece respectively while the intermediate workpiece is rotating, for plastic deformation of at least part of the metal in the hot portions and in the hot intermediate portions. The first, second, and intermediate workpieces are cooled to bond the first and second metal workpieces and the intermediate workpiece together.