The number of general-purpose pipelines in the modern world peaked at the beginning of the current millennium, but the subsequent decline had virtually no impact on market demand for the primary materials used in their construction from scratch. This is primarily due to the accumulation of thousands of kilometers of pipelines that have fallen into disrepair due to the expiration of their design lifespans and require partial or complete replacement. This situation has arisen primarily in all post-Soviet states without exception, where the transition to market-based economies has negatively impacted state-funded non-profit organizations. Utility lines for public utilities, as well as many trunk pipelines for transporting oil, natural gas, and refined products that were privatized and acquired private ownership, are currently in poor condition and regularly require repairs, so demand for products from ferrous metallurgy plants remains high. Among the types of rolled products they produce, rolled products are very popular with engineers round hot-rolled steel pipe, which allows you to solve a whole range of complex problems, and after the completion of installation work, get rid of the headaches caused by the unreliability of the equipment under your responsibility for a long time.
What can be used as a replacement for hot rolled round steel pipe if necessary?
Also, along with hot rolled steel, it is in great demand round cold-rolled steel pipe, which is obtained through the same set of sequential operations performed during the technological cycle. To understand the difference between them, it's worth taking a closer look at the few, yet significant, differences between the two production methods:
- When steel is deformed in a red-hot state, its increased ductility results in lower mechanical forces being required to complete the process. However, significant energy savings are not achieved due to the energy required for thermal processing. As a result, both types of rolled metal have approximately the same cost, and it is unlikely that one can choose one over the other based on price alone.
- After forming the cylindrical shape characteristic of both types of finished products, hot ones may bend slightly under their own weight, while cold ones retain their perfectly round cross-section. Visible irregularities in the cut can also be caused by the brittle scale formed by the reaction of iron with atmospheric oxygen, which, after crumbling, leaves shallow indentations on the surface. For this reason, when very precise end-joining, turning, or threading is required, cold-formed samples are preferred.
- When rolling steel at normal temperatures, significant mechanical stresses arise within the metal, stretching the grains into an elongated shape in the direction of the applied force. When such production costs prove undesirable for whatever reason, hot-formed rolled metal products are the choice.
Of course, it wouldn't hurt to briefly talk about other, fundamentally different, but also widely used in practice analogues.
Round electric-welded steel pipe
From fairly easily rolled flat strips of small width it is produced round electric-welded steel pipe The initial blank is bent into a cylinder with very little force, and the aligned side edges are joined by a weld using an automatically controlled electric arc in a normal air atmosphere. Due to minimal energy consumption and the simplicity of the required equipment, these products have the lowest cost among similar products. However, their scope of application is limited to operation at lower internal pressures and avoiding significant bending angles to prevent depressurization due to weld spreading.
Profiled electric-welded steel pipe
Occasionally, for laying pipelines in narrow places, a groove with a square or rectangular cross-section is used that can fit tightly to the adjacent wall or the groove welded steel pipe. It has become even more widespread as a source material for the assembly of various metal structures, as it is perfectly compatible with many other types of rolled products.