What will affect the quality of seamless steel pipes?

There are two types of factors that affect the quality of seamless pipes: steel quality and rolling process factors.

Many factors of the rolling process are discussed here. The main influencing factors are: temperature, process adjustment, tool quality, process cooling and lubrication, removal and control of sundries on the surface of the rolled piece, etc.

1. Temperature
Temperature is the most important factor affecting the quality of seamless pipes. First of all, the uniformity of the heating temperature of the tube blank directly affects the uniform wall thickness and inner surface quality of the perforated capillary, which in turn affects the wall thickness quality of the product. Secondly, the temperature level and uniformity (especially the finish rolling temperature) of the seamless steel pipe during the rolling process are related to the mechanical properties, dimensional accuracy and surface quality of the product delivered in the hot rolled state, especially when the steel billet or tube blank When it is overheated or even overburned, it will cause waste products. Therefore, in the production process of hot-rolled seamless pipes, it is first necessary to strictly follow the process requirements for heating and control the deformation temperature.

2. Process adjustment
The quality of process adjustment and work quality mainly affects the geometric and appearance quality of seamless steel pipes.
For example, the adjustment of the piercing machine and rolling mill affects the wall thickness accuracy of the product, and the adjustment of the sizing machine is related to the outer diameter accuracy and straightness of the product. In addition, process adjustment also affects whether the rolling process can be carried out normally.

3. Tool quality
Whether the tool quality is good or bad, stable or not, is directly related to the dimensional accuracy of the product, surface quality and whether the tool consumption can be effectively controlled; on the surface, the second is to affect the mandrel consumption and production cost.

4. Process cooling and lubrication
The cooling quality of perforation plugs and piercing rollers not only affects their life, but also affects the quality control of the inner and outer surfaces of the finished product. The cooling and lubrication quality of the mandrel first affects the inner surface quality and wall thickness of the seamless steel pipe; at the same time, it also affects the load during rolling.

5. Removal and control of impurities on the surface of rolled pieces
Timely and effective removal of scale on the inner and outer surfaces of capillaries and bobbins, and control of re-oxidation before rolling deformation. The inner hole of the capillary is treated with nitrogen blowing and borax spraying, and the high-pressure water at the entrance of the rolled tube is used to remove scale and fix (shrink) the diameter, effectively improving and improving the quality of the inner and outer surfaces.
 
In short, there are many factors that affect the quality of seamless steel pipes, and they are often the combined effect of various factors. Therefore, the above-mentioned main influencing factors must be effectively controlled. Only in this way can the quality of seamless steel pipes be well controlled, and hot-rolled seamless steel pipes with high dimensional accuracy, good performance and excellent quality can be produced.

Article source: https://article-realm.com/article/Finance/36441-What-will-affect-the-quality-of-seamless-steel-pipes.html