The Development of Welded Pipe as a Substitute for Seamless Pipe in China

Core Viewpoints:

1. Currently, welded pipes are increasingly replacing seamless pipes in various fields. Firstly, due to their more uniform thickness, welded pipes can be used in decorative applications and can compensate for the difficulty in manufacturing large-diameter seamless pipes (sizes above 219*6). Secondly, they can replace some structural pipes. Furthermore, with the development of high-strength welded pipe technology, some high-strength welded pipes can already replace high-end seamless pipes.

2. Compared with foreign countries, my country's welded pipe substitution for high-end seamless pipes still lags significantly. For example, in the case of oil well pipes, my country mainly produces them through long-process steel mills, and the characteristics of limited specifications and large output are not suitable for oil well supply. However, other high-end pipe varieties (such as boiler tubes, petrochemical tubes, etc.) are also being developed.

3. The future development of new energy vehicles and hydrogen energy industries presents more possibilities for welded pipes to replace seamless pipes. The replacement of seamless pipes with high-end seamless pipes not only requires leading companies to research relevant technologies, but may also require policy intervention.

4. In the past five years, the overall export volume of seamless pipes has exceeded that of welded pipes. Coupled with the international energy shortage caused by the Russia-Ukraine conflict, my country's seamless pipe exports have achieved rapid growth. From January to September 2023, the total export volume of seamless pipes in China reached 3.329 million tons, a year-on-year increase of 17.05%, mainly exported to oil-rich countries. This further confirms that my country's seamless pipes have not been replaced in terms of exports, and this is also true from a regional perspective.

Feasible areas for welded pipes to replace seamless pipes:

Compared to seamless pipes, welded pipes have the advantages of lower equipment and capital investment, simpler production processes, higher production efficiency, more specifications, and lower costs. Currently, welded pipes are increasingly replacing seamless pipes in various fields, primarily in the following aspects:

1. Decorative Applications: Because welded pipes are typically made by welding steel strips, they generally have more uniform wall thickness. They can replace steel for lightweight building structures such as doors and windows, furniture, scaffolding, electrical conduits, and high-rise shelving.

2. Size Considerations: Depending on the welding process, welded pipes are divided into straight-seam welded pipes and spiral welded pipes. Spiral welded pipes generally have higher strength than straight-seam welded pipes and can be produced with narrower blanks to create larger diameter pipes. Large-diameter seamless pipes are typically difficult to manufacture, and spiral welded pipes can overcome this limitation.

3. Structural Applications: Spiral welded pipes can also be used for piling, bridges, docks, roads, and building structures.

4. High-Strength Welded Pipes: Unlike ordinary welded pipes, high-strength welded pipes can meet the requirements of high-precision applications, such as automotive structural pipes, oilfield pipes, and boiler tubes.

China's substitution of seamless pipes for welded pipes lags significantly behind that of other countries:

The Princeton Steel Report in the US compared the proportions of welded and seamless steel pipes in seven categories: oilfield pipes, line pipes, standard pipes, machinery pipes, structural pipes, pressure pipes, and stainless steel pipes. The report showed that welded steel pipes accounted for a much larger share than seamless steel pipes, even in high-pressure boiler tubes.

Unlike the situation abroad where welded pipes replaced high-end seamless pipes, in my country, only high-end welded pipes for oilfield applications can replace seamless pipes in terms of strength. However, it's worth noting that while they can be substituted in strength, the substitution rate is not large.

The main reason for the low substitution rate is related to the steel production process. Many European and American countries primarily use short-process production, and the consumption characteristics of oil well pipes vary depending on the conditions of oil wells in different regions, featuring small batches and multiple varieties. This is similar to electric arc furnace steel production. In contrast, my country's production is mainly based on long-process production, with the advantage of fewer specifications and larger batches, making it unsuitable for the supply and sales model of oil well pipes.

The ability of welded steel pipes in the petroleum industry to replace seamless pipes and reach world-class levels is closely related to the supporting industry-academia-research collaboration. my country's petroleum system has its own welded pipe enterprises, along with supporting petroleum universities, research institutes, and testing facilities. This collaborative effort is the result of various aspects working together. However, welded pipes in other sectors in my country, such as mechanical pipes, boiler pipes, petrochemical pipes, and structural pipes, still fall far short of the strength required to replace high-end seamless pipes.

Potential future directions for welded pipes to replace seamless pipes in China:

1. The development of new energy vehicles provides more possibilities for welded pipes to replace seamless pipes.

New energy vehicles have significantly increased requirements for high strength and lightweight design. Even a one-kilogram weight reduction is crucial for improving the driving range of new energy vehicles. Currently, leading domestic companies can use special alloy steel materials combined with unique ERW pipe (straight seam resistance) technology, enabling welded pipes to replace seamless pipes in automotive stabilizer bars. This not only meets the strength requirements but also achieves lightweighting and a price advantage. However, it is worth noting that the aforementioned special alloy materials are not widespread, and only a few companies can achieve this kind of replacement for seamless pipes.

2. With the rapid development of the hydrogen energy industry, welded pipe products may see further development.

Previously, domestic pipes were mainly used in low-pressure, high-proportion hydrogen blending or high-pressure, low-proportion hydrogen blending transportation. However, on September 4th of this year, Baoji Steel Pipe Company successfully completed the first domestic long-cycle, high-pressure, high-proportion hydrogen blending test for full-size spiral welded pipes. This provides the possibility for high-pressure, high-proportion hydrogen blending welded pipe transportation in the petroleum industry, which can further reduce costs and improve efficiency. Referring to the use of high-strength welded pipes abroad, this is also one of the future directions for welded pipes to replace seamless pipes in my country.

3. Policy may play a role in the replacement of high-end seamless pipes by welded pipes.

Referring to the development model of welded steel pipes in the petroleum industry, core technologies may become key. If welded pipes in other downstream fields are to replace related high-end seamless pipes, it requires the concerted efforts of industry, academia, and research. Besides leading companies taking the lead, policy also needs to play an important role.

China's Welded Pipe and Seamless Pipe Export Situation: While my country's welded pipe production significantly exceeds that of seamless pipe, the export situation over the past five years shows that welded pipe exports only surpassed seamless pipe exports in 2020 and 2021. Seamless pipe exports saw a significant increase in 2022, before declining in 2023, but still exceeding welded pipe exports.

The rapid growth of my country's seamless pipe exports is closely related to international developments. Following the Russia-Ukraine conflict, international energy prices have been affected and remain high overall. Looking at the top 10 export destinations, most are oil-rich countries, and oil well pipes are a major export product of my country's seamless pipes. This demonstrates that seamless pipes have not been substituted in the export market.

Read more:  Why can ERW welded pipe replace seamless pipe? or China Seamless Steel Pipe Manufacturer List

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