Overview of Foreign Bimetal Composite Steel Pipe Production

Literature Overview

This 1997 review article from Shanghai Iron and Steel Metallurgical Technology Research Institute, authored by Chen Mingwei and Cai Tegang, provides a comprehensive survey of international bimetal composite steel pipe manufacturing technologies and production capabilities. Published during a period of rapid industrialization in China, this literature served as a critical knowledge transfer document for Chinese engineers seeking to understand and adopt advanced bimetal pipe fabrication technologies developed in Europe, Japan, and North America.

Core Technical Points

Major Production Methods Surveyed

The literature categorizes international bimetal composite steel pipe production into several primary technology groups, each with distinct advantages and limitations:

Production Method	Typical Cladding Thickness	Bond Strength	Production Speed	Typical Applications
Explosion cladding	1–10 mm	150–300 MPa	High (batch)	High-pressure pipelines, chemical industry
Roll bonding	0.5–5 mm	100–250 MPa	Continuous	Long-length piping, structural tubing
Hot rolling (strip cladding)	1–8 mm	Metallurgical bond	Very high (continuous)	Large-scale industrial piping
Electric slag welding (ESW) overlay	2–20 mm	Metallurgical bond	Moderate	Large diameter pipes, custom fabrication
Submerged arc welding (SAW) overlay	3–30 mm	Metallurgical bond	Moderate	Heat exchanger tubes, reactor linings
Plasma transferred arc (PTA) cladding	0.5–5 mm	Metallurgical bond	Moderate	Precision overlay, repair applications
Shot peening / mechanical bonding	1–3 mm	30–80 MPa	Moderate	Wear-resistant pipes, low-pressure service
Electrostatic spraying	0.1–1 mm	10–40 MPa	High	Thin corrosion-resistant coatings

Key International Manufacturers and Technologies

The review highlights several pioneering companies and research institutions that established the technological foundation for bimetal pipe production:

Sweden (Sandvik / SSAB): Pioneers in explosion cladding technology for nickel-alloy and stainless steel composite pipes, with production capabilities for pipes up to 1200 mm outer diameter.
Germany (SMS group / Voestalpine): Advanced roll-bonded and hot-rolled strip cladding production lines capable of continuous production of clad tubes for heat exchanger applications.
Japan (Nippon Steel / JFE): Expertise in precision clad pipe production for nuclear applications, with stringent quality control standards for weld-overlay clad pipes.
United States (Carpenter Technology / Haynes International): Specialized in nickel-alloy and superalloy clad pipes for extreme corrosion environments, including Hastelloy and Inconel overlay systems.
Finland (Outokumpu): Leaders in stainless steel clad plate and pipe production, with extensive experience in food processing and pharmaceutical industry applications.

Quality Standards and Inspection Requirements

The literature documents the international standards framework governing bimetal composite pipe production, including:

ASTM A263 / A264 / A265: Specifications for steel clad plate and pipe, defining material requirements, chemical composition, mechanical properties, and testing protocols.
API 934: Standard for welded overlay of ferrous alloy pipe and fittings, specifying overlay thickness requirements, weld procedure qualification, and inspection methods.
EN 10028-7: European standard for stainless steel clad steel plates, tubes, and shapes, covering both explosion-clad and hot-rolled clad products.
ASME IX: Welding qualification standards applicable to overlay welding procedures for clad pipes.
BS EN 10217: European standard for welded overlay of ferrous alloy pipe and fittings.

Technical Analysis of Production Methods

Explosion Cladding

Explosion cladding remains the preferred method for producing thick, metallurgically bonded clad pipes with high bond strengths. The process involves the detonation of a shaped explosive charge to accelerate a cladding sheet onto a base pipe at velocities of 2000–3000 m/s, creating a hydrodynamic metal-to-metal collision that produces a distinctive wavy or fish-scale interfacial morphology. The bond strength of explosion-clad interfaces typically exceeds 150 MPa for stainless steel/carbon steel combinations and can reach 250–300 MPa for nickel-alloy/carbon steel systems.

The primary limitations of explosion cladding include the requirement for large fabrication facilities with adequate safety clearances, the batch production nature of the process, and the difficulty of producing clad pipes with wall thickness ratios exceeding 1:4 (cladding to base metal). Additionally, the high kinetic energy of the explosion can cause significant deformation of thin-walled pipes, requiring careful process parameter optimization.

Weld Overlay Cladding

Weld overlay methods (ESW, SAW, GTAW, PTA) offer flexibility in cladding thickness and can be applied to existing pipes, making them suitable for both new fabrication and repair applications. The ESW overlay process is particularly well-suited for producing thick overlay layers (up to 20 mm) on large-diameter pipes, with production rates of 50–150 kg/h. However, the high heat input associated with ESW can cause significant dilution of the cladding material with the base metal, potentially compromising the corrosion resistance of the overlay layer.

PTA cladding offers superior control over dilution rates (typically 5–15% for single-pass applications) and produces overlay layers with near-net-shape composition. The PTA process is increasingly favored for high-value alloy cladding applications where compositional control is critical, such as Hastelloy C276 or Inconel 625 overlays on carbon steel or low-alloy steel substrates.

Engineering Practice Implications

The 1997 literature provides valuable historical context for understanding the evolution of bimetal pipe technology. Many of the technologies surveyed have since been refined and enhanced, but the fundamental principles remain applicable. For modern pressure vessel fabrication, the selection of the appropriate cladding method depends on several factors:

Required cladding thickness: Thin overlays (<2 mm) favor PTA or laser cladding; thick overlays (>5 mm) favor ESW or explosion cladding.
Cladding material: Nickel-based alloys with low melting points (Monel 400, Hastelloy C276) are amenable to most welding overlay methods; titanium and zirconium cladding require specialized processes due to their reactivity with atmospheric gases.
Production volume: High-volume production favors continuous processes (hot rolling, roll bonding); low-volume or custom applications favor welding overlay or explosion cladding.
Quality requirements: Nuclear and pressure vessel applications demand rigorous qualification testing including bond strength verification, intergranular corrosion testing, and full penetration ultrasonic examination.

Study Insights and Implications

This comprehensive review serves as an essential reference for engineers entering the bimetal pipe fabrication field. The systematic comparison of production methods, combined with the documentation of international standards and quality requirements, provides a structured framework for technology selection and process development. The literature underscores the importance of matching the cladding technology to the specific application requirements, considering not only the mechanical and corrosion performance of the final product but also the economic feasibility of the manufacturing process.

The historical perspective offered by this 1997 document is particularly valuable when considering the current state of bimetal technology. Many of the challenges identified in this review — such as controlling dilution in weld overlay, ensuring consistent bond strength in explosion cladding, and developing reliable non-destructive testing methods for clad interfaces — remain active areas of research and development. The evolution from this foundational knowledge to today's advanced production capabilities demonstrates the progressive nature of technical development in the bimetal industry.