Mandrel Bar Cleaning Facility for Seamless Pipe Carburization
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Solution Overview
Problem
The existing mandrel bar cleaning processes, particularly in seamless pipe production, fail to effectively suppress carburization on the inner surface of pipes during elongation and rolling due to incomplete removal of graphite-based lubricants, leading to operational inefficiencies and economic challenges with the use of non-graphite-based lubricants.
Innovation Solution
A mandrel bar cleaning facility that uses high-pressure water jets, with pressures ranging from 0.2 to 150 MPa, to efficiently remove graphite-based lubricants from the mandrel bar surface, allowing for the reuse of the mandrel bar with non-graphite-based lubricants without hindering operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If graphite-based lubricant is applied to the mandrel bar surface to prevent seizing during elongation and rolling, then seizing resistance is improved, but the mandrel bar surface becomes polluted with graphite, causing carburization of the pipe inner surface
Solution Approach 1:
The mandrel bar surface is cleaned of graphite pollution before the elongation and rolling process begins. This preliminary cleaning action ensures that when the graphite-based lubricant is subsequently applied, it does not mix with residual graphite particles that would cause carburization, thus maintaining both seizing resistance and preventing harmful carbon deposition on the pipe inner surface
Solution Approach 2:
Graphite particles adhering to the mandrel bar surface are removed through cleaning operations before the forming process. This extraction of harmful graphite contamination allows the mandrel bar to be reused with fresh graphite-based lubricant application, maintaining lubrication effectiveness while preventing carburization of the pipe inner surface
2Object-affected harmful factors
If the mandrel bar is cleaned to remove graphite pollution, then carburization is suppressed, but the cleaning process requires additional time and operational steps
Solution Approach 1:
The cleaning process replaces manual or mechanical sweeping methods with high-pressure water jetting. This substitution achieves thorough graphite removal from the mandrel bar surface more quickly and effectively, suppressing carburization while minimizing the time and operational complexity required for the cleaning process
Solution Approach 2:
The cleaning effectiveness is optimized by adjusting parameters such as water pressure, jet angle, and cleaning duration. By optimizing these parameters, the cleaning process achieves complete graphite removal in minimal time, balancing carburization prevention with operational efficiency and reducing overall cleaning time
3Object-affected harmful factors
If non-graphite-based lubricant is used instead of graphite-based lubricant to prevent carburization, then pipe inner surface quality is improved, but the cost of lubricant and facility investment increases significantly
Solution Approach 1:
The mandrel bar is cleaned to remove graphite pollution and then reused with fresh graphite-based lubricant application. This recovery and reuse approach allows continued use of cost-effective graphite-based lubricants while preventing carburization, avoiding the need for expensive non-graphite lubricant substitution and maintaining economic efficiency
Solution Approach 2:
A cleaning process using high-pressure water jets acts as an intermediary between the mandrel bar and the lubrication process. This intermediary cleaning step removes graphite contamination, enabling the use of economical graphite-based lubricants to be combined with quality protection against carburization, avoiding the need for expensive alternative lubricants
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
The high-pressure water jetting system effectively reduces the carbon deposition on the mandrel bar surface, preventing carburization of the inner pipe surface within a short time frame, enabling the sharing of mandrel bar conveying lines and maintaining operational efficiency.
Implementation Method 1
a cleaning device which jets high-pressure water having a water pressure of 0.2 to 150 MPa toward an outer surface of the mandrel bar
Data Source
Figure 1~2
Figure 3~5B
AI summary
It is an object of the present invention to provide a mandrel bar cleaning facility capable of effectively suppressing carburization generated on the inner surface of a pipe or tube while the pipe or tube is elongated and rolled without hindering an operation. A mandrel bar cleaning facility 15 of the present invention cleans a mandrel bar B which is pulled out of a mandrel bar conveying line after being used for elongating and rolling a pipe or tube in a mandrel mill 8. The mandrel bar cleaning facility 15 is provided with conveying devices 17, 18 that convey the mandrel bar B in the axial direction while revolving the mandrel bar B in the peripheral direction, and cleaning devices 1d that are arranged oppositely to the side of the mandrel bar B conveyed by the conveying devices 17, 18, and jet high-pressure water having a water pressure of 0.2 to 150 MPa (preferably, 20 to 150 MPa) toward the outer surface of the mandrel bar B.