Mandrel-Integrated Plasma Shielding for ERW Steel Pipe Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electric resistance welded steel pipe manufacturing, the plasma flow supply device often interferes with peripheral devices, cannot be installed at an ideal angle or distance, and is affected by air flow, leading to inadequate shielding and increased oxide defects in the welded part.
Innovation Solution
The plasma flow feeder is integrated within a mandrel inside the steel pipe, allowing for ideal angle and distance supply of plasma flow to the abutment end surfaces, with optional features like a plasma flow interrupting plate and adjusting mechanism to ensure reliable shielding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the plasma flow supply device is installed outside the steel sheet, then the device structure is simple, but the plasma flow cannot be supplied at an ideal angle or distance and interference with peripheral devices occurs
Solution Approach 1:
The plasma flow supply device is nested inside the mandrel, which is positioned within the steel sheet during welding. This internal placement allows the plasma flow to be supplied from the inside of the steel pipe at an ideal angle and distance to the abutment end surfaces, eliminating interference with peripheral devices while maintaining simple device structure.
2Ease of manufacture
If the plasma flow supply device is installed outside the steel sheet, then the installation is easier, but the shielding effect is inadequate and oxygen entrainment increases
Solution Approach 1:
Instead of supplying plasma flow from the outside of the steel sheet as in conventional methods, the invention inverts the approach by supplying plasma flow from the inside of the steel pipe through the mandrel. This internal supply method provides superior shielding effect and reduces oxygen entrainment while maintaining ease of installation.
3Device complexity
If plasma flow is supplied from outside the steel sheet, then the device configuration is simpler, but the plasma flow is affected by wind and airflow causing inadequate shielding
Solution Approach 1:
The invention creates a protected environment by supplying plasma flow from the inside of the steel pipe, where the plasma acts as a shielding gas that excludes ambient air. This internal supply method protects the plasma flow from wind and airflow interference that would occur with external supply, while the device configuration remains relatively simple.
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 configuration improves welding quality by maintaining a laminar plasma flow and reducing oxygen entrainment, suppressing oxide defects and enhancing the reliability of the electric resistance welded steel pipe.
Implementation Method 1
a plasma flow feeder (4a) that is provided in the mandrel (2) to supply the plasma flow
Implementation Method 2
a reduction action caused by the ionized plasma gas
Implementation Method 3
the abutment end portions are maintained in a state where oxygen concentration is low due to a shielding action of the abutment end portions caused by an ionized plasma gas, a reduction action caused by the ionized plasma gas
Implementation Method 4
melting abutment end surfaces of the steel sheet by induction heating using a work coil
Implementation Method 5
forming a welding seam between the abutment end surfaces while pressing the steel sheet with squeeze rolls
Data Source
Figure 1(A)~1(B)
Figure 2
Figure 3
AI summary
What is provided is an electric resistance welded steel pipe manufacturing device that is configured to perform welding while forming a strip-shaped steel sheet in a tubular shape and supplying a plasma flow to a pair of abutment end surfaces to perform shielding. The electric resistance welded steel pipe manufacturing device includes a mandrel; and a plasma flow feeder that is provided in the mandrel to supply the plasma flow.