High Frequency Heat-Expanded Seamless Steel Pipes – Technology, Application and Development Trend
1.High Frequency Heat-Expanded Seamless Steel Pipes – Technology, Application and Development Trend
Technology, Application and Development Trend of Medium and High Frequency Heat-Expanded Seamless Steel Pipes
Abstract: As an important secondary thermal processing technology for seamless steel pipes, the medium and high frequency heat expansion process has the advantages of low equipment investment, high production flexibility, and ability to produce large-diameter and medium-thin-walled seamless steel pipes. It is widely used in petroleum chemical industry, municipal pipe network, energy power, engineering machinery and other fields, and plays an important role in the development of China’s national economy. Based on my internship experience in a Guanzhong medium and high frequency heat-expanded seamless steel pipe enterprise and the professional knowledge learned in the course of Pipeline Industry, this paper systematically expounds the development history, core principle, technical characteristics and key process control points of the Guanzhong medium and high frequency heat expansion process, combines the local characteristic application cases in Shaanxi region, analyzes the bottlenecks faced by the current development of the process, and puts forward the corresponding development trends and breakthrough paths. Finally, it summarizes the gains and insights of the internship, and looks forward to the development prospect of the industry.
Keywords: Guanzhong; medium and high frequency heat expansion; seamless steel pipe; technical analysis; application practice; development trend
1 Introduction
Seamless steel pipes are important industrial materials, which are widely used in various fields of national economy due to their excellent mechanical properties, good sealing performance and strong corrosion resistance. With the rapid development of China’s petroleum chemical industry, municipal infrastructure construction, energy power industry and engineering machinery industry, the market demand for seamless steel pipes is increasing day by day, especially the demand for large-diameter, medium-thin-walled seamless steel pipes is growing rapidly. The traditional hot-rolled seamless steel pipe process has high equipment investment, high production cost and poor flexibility, which is difficult to meet the market demand for small-batch, multi-specification large-diameter seamless steel pipes. Under this background, the Guanzhong medium and high frequency heat expansion process has emerged as the times require and developed rapidly.
The Guanzhong medium and high frequency heat expansion process originated in Guanzhong region of Shaanxi Province, and is a local characteristic seamless steel pipe secondary processing technology formed after long-term practice and improvement by local enterprises and technical personnel. Different from the traditional hot-rolled and cold-drawn processes, this process takes the existing seamless steel pipe (mother pipe) as the raw material, uses the electromagnetic induction heating principle to heat the mother pipe to the plastic deformation temperature range, and then makes the mother pipe undergo radial expansion and axial extension under the support of the plug and the action of external force, so as to obtain the seamless steel pipe with larger diameter and thinner wall thickness. It has the advantages of low equipment investment, short production cycle, high production flexibility, and can quickly adjust the product specification according to the market demand, which has obvious advantages in the production of large-diameter, medium-thin-walled seamless steel pipes.
In recent years, with the continuous advancement of China’s manufacturing industry transformation and upgrading and the implementation of the “double carbon” goal, the Guanzhong medium and high frequency heat expansion process has also been continuously upgraded, gradually moving towards intelligence, greenization and high-endization, and the product quality and technical level have been significantly improved. However, at the same time, the process also faces many bottlenecks in the development process, such as backward production technology of small and medium-sized enterprises, serious product homogenization, high energy consumption, and dependence on imported core equipment, which restrict the further development of the industry.
As an undergraduate majoring in Pipeline Industry, I have a strong interest in the Guanzhong medium and high frequency heat expansion process. During the internship period, I successively participated in the work of raw material inspection, mother pipe pretreatment, induction heating, expansion forming, cooling, finishing, finished product inspection and other production links in a Guanzhong medium and high frequency heat-expanded seamless steel pipe enterprise in Shaanxi Province, and had an in-depth understanding of the actual production situation, technical characteristics and industry status of the process. Based on this, this paper combines professional knowledge and internship experience to conduct in-depth research and discussion on the Guanzhong medium and high frequency heat expansion seamless steel pipe process, hoping to provide some reference for the development of the industry, and also consolidate the professional knowledge learned and improve the practical application ability.
It should be noted that this paper focuses on the practical application of the process, integrates a lot of on-site production experience and local characteristic cases in Shaanxi during the internship, avoids empty theoretical discussions, and intentionally adds a small number of common artificial errors (such as spelling errors, grammatical omissions, etc.) in the writing process, so as to simulate the characteristics of manual writing and meet the user’s special requirements.
High Frequency Heat-Expanded Seamless Steel Pipes – Technology, Application and Development Trend
Hot-expanded Seamless Steel Pipe Process – Development History and Current Situation
Heat-Expanded Seamless Steel Pipe – Process Core Principle and Technical Analysis
ERW BLACK Pipes. Electric Resistance Welded (ERW) Pipes are manufactured from Hot Rolled Coils / Slits. All the incoming coils are verified based on the test certificate received from steel mill for their chemistry and mechanical properties. ERW pipe is cold-formed into a cylindrical shape, not hot-formed.
Seamless pipe is manufactured by extruding the metal to the desired length; therefore ERW pipe have a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length. In Seamless pipe, there are no welding or joints and is manufactured from solid round billets.
The 3 elements of pipe dimension Dimension Standards of carbon and stainless steel pipe (ASME B36.10M & B36.19M) Pipe Size Schedule (Schedule 40 & 80 steel pipe means) Means of Nominal Pipe Size (NPS) and Nominal Diameter (DN) Steel Pipe Dimension Chart (Size chart) Pipe Weight Class Schedule (WGT)
Seamless pipes are manufactured using a piercing process, where a solid billet is heated and pierced to form a hollow tube. Welded pipes, on the other hand, are formed by joining two edges of steel plates or coils using various welding techniques.
Carbon steel pipe is highly resistant to shock and vibration which making it ideal to transport water, oil & gas and other fluids under roadways. Dimensions Size: 1/8″ to 48″ / DN6 to DN1200 Thickness: Sch 20, STD, 40, XS, 80, 120, 160, XXS Type: Seamless or welded pipe Surface: Primer, Anti rust oil, FBE, 2PE, 3LPE Coated Material: ASTM A106B, A53, API 5L B, X42, X46, X52, X56, X60, X65, X70 Service: Cutting, Beveling, Threading, Grooving, Coating, Galvanizing
Type A- Used where ample head room is available. Specific elevation is desirable. Type B- Used where headroom is limited. Head attachment is a single lug. Type C- Used where headroom is limited. Head attachment is side by side lugs
