What are the factors and controls that affect the quality of seamless pipes?

What are the quality factors that affect seamless pipes & tubes? Let’s analyze them in detail:

(1) Temperature

The quality of steel pipes is primarily affected by temperature. The uniformity of the heating temperature of the steel pipe blank directly affects the uniform wall thickness and inner surface quality of the perforated steel pipe capillary tube, which in turn affects the wall thickness quality of the seamless pipe product. The temperature and uniformity of the steel pipe during rolling, particularly the final rolling temperature, are related to the mechanical properties, outer diameter, dimensional accuracy, and surface quality of the product in its hot-rolled state. Overheating of the steel billet or tube billet can result in waste products. In the production process of hot-rolled seamless pipes, it is crucial to heat and control the deformation temperature strictly according to process requirements.

(2) Process adjustment

Process adjustments and work quality have a significant impact on the geometric appearance of steel pipes. For instance, the accuracy of wall thickness in seamless pipe products is affected by the adjustment of the piercing and pipe rolling machines, while the adjustment of the sizing machine is related to the outer diameter accuracy and straightness of the seamless steel pipe. It is important to note that process adjustments can also impact the normal progression of the rolling process.

(3) Tool quality

The quality of the tool is directly related to the dimensional accuracy and surface quality of the seamless pipe, as well as the tool consumption. Additionally, the quality of the mandrel's surface treatment (chrome plating) affects both the inner surface of the steel pipe and mandrel consumption and production costs.

(4) Process cooling and lubrication

The quality of the perforation head and roller's cooling not only affects their service life but also impacts the quality control of the internal and external surfaces of the seamless pipe. The cooling and lubrication quality of the mandrel affects the inner surface quality of the seamless steel pipe, the wall thickness accuracy of the seamless pipe, and the mandrel's consumption and load during rolling.

(5) Removal and control of debris on the surface of rolled pieces

This refers to the timely and effective removal of oxide scale from the inner and outer surfaces of steel pipe capillaries and raw pipes before rolling deformation, as well as controlling re-oxidation. Nitrogen blowing and borax spraying treatment of the inner hole of capillary steel pipes, pipe rolling, and high-pressure water descaling at the fixed (reduction) diameter entrance can effectively improve the quality of the inner and outer surfaces.