Steel seamless tubing process

Steel seamless tubing is a long pipe with no welds on the surface. It is made of a whole round steel and is widely used in petroleum, natural gas, chemical industry, electric power, aerospace and other fields. According to the production method, seamless tubes can be divided into hot-rolled tubes, cold-rolled tubes, cold-drawn tubes, extruded tubes, etc.

Seamless tubing production process:

1. Hot-rolled seamless tubes are generally produced on automatic pipe rolling units. The solid tube blank is inspected and surface defects are removed, cut into the required length, centered on the perforated end of the tube blank, and then sent to the heating furnace for heating and piercing on the punching machine. It continues to rotate and advance during piercing holes. Under the influence of the rollers and the end, the tube blank is hollow gradually, which is called gross pipe. Then it is sent to the automatic pipe rolling machine to continue rolling. Finally, the wall thickness is evened by the leveling machine, and the diameter is determined by the sizing machine to meet the specification requirements. The use of continuous pipe rolling units to produce hot-rolled seamless steel tubes is a more advanced method.

2. If you want to obtain seamless tubes with smaller size and better quality, you must use cold rolling, cold drawing or a combination of the two. Cold rolling is usually carried out on a two-roll mill, and the steel pipe is rolled in an annular pass composed of a variable cross-section circular groove and a fixed conical head. Cold drawing is usually performed on a 0.5 to 100T single-chain or double-chain cold drawing machine.

3. The extrusion method is to place the heated tube blank in a closed extrusion cylinder, and the perforation rod and the extrusion rod move together to make the extrusion part extruded from the smaller die hole. This method can produce steel pipes with smaller diameters.

Classification of seamless tubing:
1. According to different production methods, it can be divided into hot-rolled tubes, cold-rolled tubes, cold-drawn tubes, extruded tubes, etc.
2. According to the shape, there are round tubes and special-shaped tubes. In addition to square tubes and rectangular tubes, special-shaped tubes also include oval tubes, semi-circular tubes, triangular tubes, hexagonal tubes, convex-shaped tubes, plum-shaped tubes, etc.
3. According to different materials, they are divided into ordinary carbon structural pipes, low alloy structural pipes, high-quality carbon structural pipes, alloy structural pipes, seamless stainless steel pipes, etc.
4. According to special purposes, there are boiler tubes, mechanical tubes, geological pipes, oil pipes, etc.

The import and export situation of seamless tubing:

The import and export situation of China's seamless tubes shows that export volume continues to grow, while import volume has declined. ‌
1. In terms of exports, China's seamless pipe exports have gradually increased since 2020. Especially in 2023, the total seamless tube exports will reach 5.6643 million tons, setting a new high. The proportion of that year's output is 17.98%, exceeding the 2014 level. ‌This shows that China’s seamless pipe export volume and proportion are increasing.

2. In terms of imports, ‌ Although specific data shows that China’s seamless steel tube imports have declined, ‌ for example, China’s seamless steel pipe imports in 2020 were 52,600 tons, ‌ a year-on-year decrease of 22.99%, ‌ showing that the import volume is in reduce.

In addition, the average export price of China's seamless tubes will fall significantly in 2023, which may be beneficial to the export of seamless tubes, because the price advantage is an important factor in promoting exports. ‌From the perspective of exporting countries, ‌China's seamless pipes are mainly exported to countries along the "Belt and Road", ‌such as India, ‌United Arab Emirates, ‌South Korea, ‌Thailand, ‌Indonesia, ‌Oman, ‌Turkey, etc. ‌These The country has been among the top exporters of seamless pipes in China for many years in a row.

To sum up, China's seamless tube exports show a trend of increasing volume and falling prices, while import volume has decreased, which shows that China's status and influence in the global seamless tubing market are constantly increasing. ‌

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