1、 Standard product information for stainless steel seamless ultra long coils:
（1） Standard for seamless ultra long stainless steel coils
Production method: Stainless steel seamless ultra long coils are manufactured using the Pier format rolling process, seamless cold drawing, and vacuum bright heat treatment process.
Outer diameter OD: 1/8 "-1" (diameter between 3mm and 25mm)
Wall thickness WT: 0.020 "-0.083" (0.5mm -3mm)
Tolerance range: Outer diameter tolerance: ± 0.08mm (0.00315 "), wall thickness tolerance: ± 0.08mm (0.00315")
Length: 100M~10000M (Taking the seamless coil pipe with a weight of 100 kilograms and a specification of 6 * 1, made of standard material 316L, as an example, the basic non welded length of a single coil should reach 800 meters)
Materials: 304/304L, 316/316L, 321, 904L, 8825, 2205, and other materials.
Production standards: ASTM (ASME) SA/A312/A213/A269 and DIN, GB, JIS
2、 Production and manufacturing process:
1. The production process of ultra long stainless steel seamless coils adopts Pier format rolling and seamless cold drawing to ensure the material's strength, flexibility, and continuity.
2. The vacuum bright heat treatment process adopted in the heat treatment process ensures that the inner and outer surfaces of the ultra long stainless steel seamless coil do not come into contact with oxygen and do not produce oxide skin, making the inner and outer surfaces of the ultra long stainless steel seamless coil cleaner, brighter, and more delicate, with a surface roughness of less than 0.4 μ m; The hardness of the pipe (HRB ≤ 90) allows users to easily bend and connect without leakage, making it suitable for various complex environments.
3、 Inspection and acceptance:
（1） Inspection items, sampling quantities, and test methods for stainless steel seamless ultra long coils
Due to the long length of stainless steel seamless ultra long coils, each coil should be cut open from the middle position to take a sample of the middle section for inspection. The length of the sample should be greater than 50mm.
|
序号 |
检验项目 |
试验方法 |
取样数量 |
|
1 |
化学成分 |
GB/T 222 GB/T 223 |
每炉取一个试样 |
|
2 |
拉伸试验 |
GB/T 228 GB/T 6397 |
每批在两盘管上个各取一个试样 |
|
3 |
高温力学试验 |
GB/T 3652 |
每批在两盘管上个各取一个试样 |
|
4 |
洛氏硬度试验 |
GB/T 230 |
每批在两盘管上个各取一个试样 |
|
5 |
压扁试验 |
GB/T 246 |
每批在两盘管上个各取一个试样 试样长＞50mm |
|
6 |
扩口试验 |
GB/T 242 |
每批在两盘管上个各取一个试样 试样长＞50mm |
|
7 |
液压试验 |
GB/T 241 |
逐盘 |
|
8 |
超声波探伤检验 |
GB/T 4163 GB/T 577 |
逐盘 |
|
9 |
涡流试验 |
GB/T 7735 |
逐盘 |
|
10 |
晶间腐蚀试验 |
GB/T 4334.1~5 GB/T 1223 |
每批在两盘管上个各取一个试样 |
|
11 |
粗糙度 |
GB/T 1031 |
每批在两盘管上个各取一个试样 |
|
11 |
表面质量 |
目测 |
逐盘 |
|
12 |
尺寸 |
精度0.01mm量具 |
逐盘 |
（2） Special requirements
The standard hydraulic test pressure for stainless steel seamless ultra long coil is 10MPa~35Mpa. If there are special requirements, high-pressure testing can be carried out, and the test pressure can reach 200Mpa.
4、 Installation and use:
1. The biggest difference between stainless steel seamless ultra long coil pipe and ordinary stainless steel seamless steel pipe lies in the maximum reduction of the number of joints during use; During the installation process, the use of joints was significantly reduced, and the safety of the entire pipeline system was completely improved, enhancing the safety of system operation
2. In use, it can be cut and bent according to the required length requirements, reducing waste and lowering costs. Especially in the installation of conveying pipelines, it saves installation joints and improves safety performance.
3. Reducing the risk of system leakage and maintenance costs in hydraulic systems, ultra long seamless coils will be a good choice.
5、 Product packaging method:
Usually, woven bags or plywood boxes are used for packaging, with plywood wooden shafts for convenient transportation and storage; Stainless steel coil products will be packaged in rolls or wrapped on wooden shafts, making sea, land, and air transportation convenient, reducing transportation costs and facilitating customer inventory storage.
6、 Usage of the product:
1. Stainless steel seamless ultra long coil is cut using a dedicated electric coil cutting machine and a manual coil cutting machine. The electric coil cutting machine realizes fully automatic straightening, fixed length cutting, and chip free cutting of stainless steel seamless coils, with high cutting accuracy and fast speed, and a tolerance of ± 0.2MM for every 1000 meters of cutting accuracy. The manual coil cutting machine does not require power supply, is small in size, light in weight, convenient and convenient, and is suitable for cutting small amounts of coils.
2. The product adopts a sleeve type pipe joint connection method, which has the characteristics of reliable connection, high pressure resistance, good sealing, strong temperature resistance, and convenient installation. It is widely used in industries such as instruments, petrochemicals, power, and gas.
7、 Application scope:
Stainless steel seamless ultra long coils are widely used in petroleum drilling, shipbuilding, aerospace and petrochemical refining equipment, spiral wound tube heat exchangers, wound tube heat exchangers, and chemical industries for cold treatment, gas pipelines, fluid pipelines, steam insulation cables, stainless steel heat tracing coils (heat tracing coils), high pressure fluid pipelines, stainless steel insulation cables, PVC sheathed anti-corrosion stainless steel cables, umbilical cables, and other industries.
8、 The difference between stainless steel seamless ultra long coil and stainless steel welded (seam) coil
（1） Stainless steel welded (seam) coils
Stainless steel welding (with seams) uses stainless steel strips for online welding, bright annealing, and one-time forming. The welding rods or wires used in the welding area cannot be completely consistent with the material of the steel strip itself, which is prone to corrosion and leakage hazards starting from the weld position.
Stainless steel welding requires the use of stainless steel tungsten needles. When welding thick walled pipes, wear and tear can lead to uneven wall thickness of the welded pipe, resulting in leakage in areas with thin wall thickness. Due to the uncontrollable wear of tungsten needles, current users estimate that tungsten needles may have worn out. After removal and grinding, they cannot guarantee a 100% uniform wall thickness of stainless steel welded (seam) coils.
Stainless steel welded (seam) coils generally withstand a pressure of 20MPa. In high-pressure environments, safety cannot be guaranteed and leaks are prone to occur.
（2） Stainless steel seamless ultra long coil pipe
Stainless steel seamless ultra long coils are produced using seamless technology starting from raw materials. The finished product made through multiple cold drawing and vacuum heat treatment processes has a uniform wall thickness and a delicate surface, which can withstand high pressure of 80-100MPa and ensure the safety of high-pressure gas transportation pipelines.
At the meeting, Zhang Zhifang, Executive Chairman of the Stainless Steel Branch of the China Iron and Steel Industry Association, introduced the relevant development situation of the stainless steel industry in 2023 and the development direction in 2024. Representatives of stainless steel and upstream and downstream industry associations in the industry chain respectively introduced the operation situation of their respective industries in 2023, as well as the demand and application of stainless steel.
Su Changyong, Deputy Secretary General of China Iron and Steel Industry Association and Party Secretary and President of Metallurgical Industry Press, stated in his speech that there is still room for growth in stainless steel consumption. He believes that the current high export volume of stainless steel can still be maintained for a period of time. At the same time, he proposed that the high-quality development of the stainless steel industry should pay attention to issues such as overcapacity, raw material supply, stainless steel innovation, and changing the image of stainless steel.
The invention discloses a preparation method for aviation grade martensitic sulfur-containing free cutting stainless steel, which includes adding industrial pure iron, nickel plate, low-carbon chromium iron, and the steel grade return material to an electric furnace for melting, adjusting the steel composition to control the composition, according to weight percentage: C: 0.22~0.25%, Si: 0.10~0.25%, Mn: 1.10~1.20%, P: 0.10~0.13%, Cr: 12.50~13.50%, Ni: 1.65~1.90%; Insert sulfur powder sealed with a thin tube into the steel liquid, stir evenly, then add BaAlSi alloy for final deoxidation, and then pour it out of the furnace into an electric slag billet; Perform electroslag remelting on the electroslag billet, using an electroslag remelting slag system that includes 30-40 wt% CaF2 powder, 25-35 wt% Al2O3 powder, 20-30 wt% SiO2 powder, 3-7 wt% MgO powder, and 3-7 wt% metallic manganese particles; After the electroslag remelting of the ingot, it is sent to the forging hot working furnace for heating, and then forged. After forging, it is sent to the annealing furnace for annealing heat treatment to obtain martensitic sulfur-containing free cutting stainless steel for aviation. This preparation method can effectively control the content of sulfur and manganese elements, and improve the comprehensive yield of Y25Cr13Ni2.
Production capacity of crude steel in various regions
According to the OECD forecast, Asias crude steel production capacity ranks first globally in 2023, estimated to be 1.6566 billion tons, an increase of 40.1 million tons or 2.5% compared to 2019; Next is Europe, with a production capacity of 294.3 million tons, an increase of 7 million tons or 2.4% compared to 2019. Among them, EU countries have 213.6 million tons, a decrease of 2.32 million tons or 1.1% compared to 2019, while other European countries have 80.7 million tons, an increase of 9.3 million tons or 13.0% compared to 2019; North America ranks third with a production capacity of 165.8 million tons, an increase of 11.6 million tons or 7.5% compared to 2019; The production capacity of CIS countries is 145.1 million tons, an increase of 1.7 million tons or 1.2% compared to 2019; The production capacity in Latin America is 75.9 million tons, an increase of 2 million tons or 2.7% compared to 2019; The production capacity of Middle Eastern countries is 103.3 million tons, an increase of 22.6 million tons or 28.0% compared to 2019. The production capacity in Africa is 51.4 million tons, an increase of 6.8 million tons or 15.1% compared to 2019; The production capacity of Oceania is 6.4 million tons, which has remained stable since 2019. The global crude steel production capacity is 2.4986 billion tons, an increase of 91.6 million tons or 3.8% compared to 2019.
