In railway engineering, anti-corrosion sleepers are the most fundamental load-bearing components in track structures. Many people believe that as long as the anti-corrosion oil is immersed in the wood through high pressure, it can ensure the long-term durability of the sleepers. But in reality, the effectiveness of anti-corrosion treatment is closely related to a seemingly simple process - scratch treatment. This process not only directly affects the penetration effect of anti-corrosion oil, but also relates to the service life of the entire sleeper and the safety of railway operation.
1、 Scratches: the "navigation channel" of anti-corrosion oil
The natural structure of wood is like a complex maze. The internal conduits and cell walls of commonly used sleeper materials such as pine and oak are tightly arranged to form a natural barrier. If anti-corrosion oil wants to penetrate deep into the core of wood, relying solely on high-pressure treatment is like using brute force to break through layers of barriers, with low efficiency and high cost. Scratch processing was born to solve this problem.
Taking pine pillows as an example, in the scoring process, the high-speed rotating blade will carve regular knife marks on the surface of the pillow with a depth of not less than 10 millimeters and a length exceeding 10 millimeters. These seemingly simple scratches actually construct a three-dimensional permeation network on the surface of the wood. When the sleepers enter the high-pressure impregnation tank, the anti-corrosion oil will quickly penetrate along these manually excavated "channels". Experimental data shows that after standardized scoring treatment, the uniformity of anti-corrosion oil distribution on sleepers is improved by about 35%.
2、 Technical details determine success or failure
Scratching treatment is not simply about making a few cuts. The railway engineering standards have strict technical requirements for this process: each knife mark must maintain a depth of at least 13 millimeters (high-quality pine wood allows for 10 millimeters), the spacing between adjacent knife marks must be precisely controlled, and the leakage rate of the pillow surface should not exceed 5%. Behind these numbers is the accumulated experience of countless engineering practices.
During the operation, workers need to adjust the tool holder parameters in real time according to the characteristics of the wood. When encountering natural defects such as knots and cracks, non-conforming products must be immediately removed. The upward fixing method of the pillow surface is not only for the convenience of nailing the year identification, but also to ensure the quality of the scratches on the main pressure bearing surface. When blade wear leads to insufficient depth of scratches, timely replacement of the tool becomes the key to ensuring quality. The control of these details directly affects the effectiveness of the later anti-corrosion treatment.
3、 The cost of being ignored
Some informal manufacturers often omit or simplify the scoring process in order to reduce costs. Untouched wood often only retains anti-corrosion oil at a depth of a few millimeters on the surface. In humid and rainy areas, such sleepers will experience internal decay within a few years.
More seriously, non-standard scratches may have the opposite effect. Shallow knife marks (<8 millimeters) can lead to "false penetration" phenomenon, while deep scratches (>15 millimeters) may damage the mechanical structure of the wood. Excessive leakage rate can lead to local areas becoming blind spots for corrosion prevention, and these hidden dangers will eventually evolve into safety hazards under the repeated action of train dynamic loads.
4、 The engineering wisdom of engraving technology
Modern scoring equipment has achieved automated control, but the experience of technicians is still indispensable. Skilled operators can determine the degree of tool wear based on the color of wood chips and adjust the feed speed according to the hardness of the wood. In the scoring process, it is necessary to balance three key elements: ensuring penetration depth, maintaining wood strength, and controlling processing efficiency. This balancing art is the essence of engineering technology.
The anti-corrosion treatment of sleepers is a systematic engineering process, and the scoring process is like building a "capillary network" for wood. It allows anti-corrosion oil to penetrate into the "texture" of wood, transforming ordinary wood into engineering materials that can withstand decades of wind and rain erosion. In today's pursuit of efficient anti-corrosion technology, we need to pay more attention to these basic but critical process links. After all, sleepers carry not only steel rails and trains, but also the safety of millions of passengers' lives.
