Defect control method of cold drawn seamless pipe

Cold drawn seamless tubing is a precision steel pipe with high dimensional accuracy and good surface finish for mechanical structures and hydraulic equipment. Widely used in petroleum, chemical industry, boiler, power station, ship, machinery manufacturing, automobile, aviation, aerospace, energy, geology, construction and military industry, etc.

In the production process, the quality of cold-drawn seamless pipes is up and down. In order to save resources and improve material utilization, it is necessary to analyze and control the defects in the production process of cold-drawn seamless pipes. So what are the defect control methods?

1. Control the carbon content in the steel as much as possible to avoid the peritectic reaction zone and control the upper or lower limit.

2. The vibration stability should be monitored to ensure that the lateral deflection of the vibration is not greater than 0.2mm and the longitudinal deflection is not greater than 0.4mm.

3. Strict nozzle assembly ensures good nozzle alignment, prevents drift, and ensures uniform solidification of special-shaped pipes.

4. Improve the accuracy of the fan part, especially the crystallizer and the zero part, and if severe bending is found, replace the pinch roller of the zero part.

5. Control the superheat of the steel in the cold-drawn seamless pipe, determine the appropriate wire drawing speed system, and prevent the shell from being too high in temperature and too thin in the wire drawing speed.

6. Select the appropriate slag according to the characteristics of the special steel pipe, appropriately increase the viscosity of the mold slag, and improve the heat transfer uniformity of the mold slag. There are few principles when adding mold slag.

7. Appropriately increase the contact degree between the narrow foot roller and the billet to prevent the cold-drawn seamless pipe from protruding, but the foot roller should not be adjusted too hard, otherwise it may cause large resistance to the casting.

8. Ensure that the water gap of the crystallizer is uniform, improve the quality of the crystallizer equipment, prevent severe wear of the crystallizer and shedding of the coating, realize weak cooling of the crystallizer, and reasonably control the cooling intensity.

9. In order to prevent the large deflection angle of serious depression, the hydraulic system of the fan section should be well maintained. On-site inspection to prevent hydraulic loss or fan section lifting, improve the quality of the pinch rollers in the fan-shaped part and conduct daily on-site inspections to prevent pinch rollers from breaking, and stop the machine immediately after the deviation angle is seriously sunken to avoid excessive losses. Handle hydraulic system failure or replace sectors after shutdown.

Cold-drawn seamless pipe is a product that has appeared in recent years, mainly because the inner hole and outer wall have strict tolerances and roughness. Compared with seamless pipes, cold-drawn (rolled) finished products have high precision, good surface quality, superior performance of steel pipes, and denser metals.

Article source: https://article-realm.com/article/Finance/40189-Defect-control-method-of-cold-drawn-seamless-pipe.html