Mould copper tubes are critical to continuous casting operations, as their material directly affects billet quality and production efficiency. Below is a concise yet detailed breakdown of the most widely used options, aligned with industry standards and real-world practices.

1. Phosphorus-Deoxidized Copper (TP2) 

Core Details (ASTM B75/GB/T 1527-2021 Compliant)

-Composition: Minimum 99.5% Cu+Ag, with phosphorus (P) controlled at 0.015%–0.04%—this formulation removes oxygen to boost workability while keeping costs low.

-Key Traits: Delivers reliable thermal conductivity for steady billet solidification and is easy to shape into square, rectangular, or circular cross-sections. Its main limitation, however, is lower high-temperature strength and wear resistance compared to alloyed alternatives.

-Typical Uses: The top-selling mold copper tube globally, it dominates plain carbon steel and low-alloy steel casting—especially in small-billet casters (e.g., 120×120mm, 125×125mm) where cost-effectiveness and basic performance suffice.

2. Silver-Copper (Cu-Ag0.1) 

Core Details (Metallurgically Validated)

- Composition: Minimum 99.9% Cu+Ag, with 0.08%–0.12% silver (Ag)—a precise dosage that enhances performance without sacrificing conductivity.

- Key Traits: Silver raises copper’s recrystallization temperature by ~50°C (to 318–326°C), preventing softening at typical operating temps (250–320°C). Its thermal conductivity (368 W/(m·K) at 20°C) also outperforms copper-chromium-zirconium alloys, reducing billet surface defects.

-Typical Uses: Ideal for high-speed casting lines (3–5 m/min for billets) and specialty steel production (e.g., stainless steel, alloy steel). As noted in World Steel Association 2023 data, it is more widely adopted in international markets where casting efficiency and surface quality are prioritized.

3. Copper-Chromium-Zirconium (Cu-Cr-Zr) 

Core Details (ASTM B152-22 Compliant)

-Composition: Minimum 98.0% Cu+Ag, with 0.3%–1.2% chromium (Cr) and 0.05%–0.25% zirconium (Zr)—a precipitation-hardened alloy that forms strengthening precipitates.

-Key Traits: Offers exceptional high-temperature performance, including creep resistance, thermal fatigue resistance, and wear resistance. It lasts 2–3x longer than TP2 (even without nickel plating) and balances strength with conductivity—critical for high-stress applications.

-Typical Uses: Suited for demanding scenarios like slab casting (width 1500–2200mm) and high-end specialty steel (e.g., bearing steel, high-strength steel). It is commonly deployed in large-scale hot rolling lines for heavy-duty casting, with application validity confirmed in industry technical case studies.

Specialized Alloys (Niche Applications) 

Custom alloys like copper-chromium-zirconium-arsenic (Cu-Cr-Zr-As) or copper-magnesium-zirconium (Cu-Mg-Zr) offer enhanced properties (e.g., corrosion resistance, extra strength). However, their complex manufacturing and 30%–50% higher costs limit use—per China Nonferrous Metals Industry Association 2024 data, they make up <5% of global shipments, reserved for ultra-specialized needs (e.g., nuclear-grade steel casting).

In summary, material choice follows application needs: TP2 for cost-sensitive conventional production, Cu-Ag0.1 for high-speed/quality casting, and Cu-Cr-Zr for heavy-duty high-end manufacturing—together driving the global mold copper tube market.