Defect control method of cold drawn seamless pipe

Cold  drawn seamless pipes are precision steel pipes with high dimensional accuracy and good surface finish for mechanical structures and hydraulic equipment. Widely used in petroleum, chemical industry, boilers, power stations, ships, machinery manufacturing, automobiles, aviation, aerospace, energy, geology, construction and military industries.

In the production process, the quality of cold drawn seamless pipe is good and bad. 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 pipe. So what are the defect control methods?

Defect control of cold drawn seamless pipes:

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 mold and the zero part. If serious bending is found, replace the clamping roller of the zero part.

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

7. Appropriately increase the contact degree between the narrow foot roll and the casting billet to prevent the cold drawn seamless pipe from protruding, but the foot roll 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 the crystallizer from being seriously worn and the coating falls off, realize the weak cooling of the crystallizer, and reasonably control the cooling intensity.

9. In order to prevent the large declination angle of serious depression, the maintenance of the hydraulic system of the fan section should be done well, and the on-site inspection should be done to prevent the hydraulic loss or the lifting of the fan section, improve the quality of the pressing roller of the fan-shaped part, and carry out daily on-site inspection to prevent the pressing Immediately stop the machine after the roll is broken and the deviation angle is seriously dented to avoid excessive losses. Deal with hydraulic system failure or replace sector after shutdown.

What are the differences and advantages of cold drawn seamless pipe and general seamless pipes?

The difference:

1. The main feature of ordinary seamless steel pipes is that they have no welded seams and can withstand greater pressure; the products can be very rough as-cast or cold-drawn parts.

2. 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.

Advantage:

1. The outer diameter of the seamless pipe size is smaller;

2. High precision and small batch production;

3. The cold drawn (rolled) finished product has high precision and good surface quality;

4. The cross-sectional area of ​​the steel pipe is more complicated;

5. The performance of the steel pipe is more superior, and the metal is relatively dense.

Article source: https://article-realm.com/article/Finance/22026-Defect-control-method-of-cold-drawn-seamless-pipe.html