Description

Marine hardware procurement in Southeast Asia keeps copper alloys under continuous exposure to seawater, humid air, and chloride-rich spray. For a buyer sourcing bronze plates, the practical question is seldom limited to which alloy suits a corrosive environment. Procurement teams must also establish which grade, temper, cross-section, and standard can be documented before the order is placed. Jiangsu Xinxiangsheng Special Steel Co., Ltd. — known in trade channels as Xinxiangsheng Special Steel — works from a defined material classification and a documented production chain, which gives marine buyers a repeatable way to specify plates, tubes, busbars, and conductive forms.

How Copper Materials Are Classified by Composition

Industrially, copper materials are categorized by composition into two main groups: pure copper and copper alloys. Common alloys include brass (copper-zinc), bronze (copper-tin, copper-aluminum, etc.), and cupronickel (copper-nickel). Based on oxygen content and deoxidation method, pure copper is further subdivided into tough-pitch copper (electrolytic tough-pitch copper), oxygen-free copper, and phosphorus-deoxidized copper. Oxygen content directly affects welding, formability, and resistance to hydrogen embrittlement, which makes it a key factor in material selection and technical inquiries.

• Pure Copper (Red Copper): superior electrical and thermal conductivity; used for busbars, conductive components, heat exchangers, and water/gas piping. Representative grades: T1/T2/T3, TU1/TU2, TP1/TP2.
• Brass (Copper-Zinc Alloy): high strength, good machinability, golden-yellow appearance; used for tubing, hardware, valves, lighting fixtures, and connectors. Representative grades: H59–H80.
• Bronze / Cupronickel: alloyed with elements such as tin, aluminum, or beryllium (bronze) or nickel (cupronickel); used for elastic components, wear-resistant parts, and applications in marine or corrosive environments.
• Specialized Conductive Forms: copper busbars, braided copper wire/flexible connectors, and stranded copper wire; used for high- and low-voltage electrical equipment, switchgear, and transformer connections and grounding.

Grades and Chemical Composition Reference Ranges

Pure Copper (Tough-pitch Copper): T1, T2, and T3, with copper content decreasing sequentially. T1 is ≥ 99.95%, T2 ≥ 99.90%, and T3 ≥ 99.70%, primarily for general-purpose processed materials and electrical conductive components.

Oxygen-free Copper: TU1 and TU2, characterized by high copper content and extremely low oxygen content (TU1 ≥ 99.97%, TU2 ≥ 99.95%); widely used in electronics, vacuum applications, and high-specification welded components.

Phosphorus-deoxidized Copper: TP1 and TP2, both with copper content ≥ 99.90%, deoxidized through the addition of phosphorus (0.004%–0.040%). TP2 is the most commonly used grade, applied in water pipes, gas lines, heat exchangers, and air conditioning tubing.

Brass (Copper-Zinc Alloy): copper content rises with the grade — H59 (57–60%), H62 (60.5–63.5%), H65 (63–66%), H68 (67–70%), and H80 (79–81%), with the remainder being zinc.

Corresponding ASTM Grades: C11000 is electrolytic tough-pitch copper (Cu ≥ 99.90%, equivalent to T2); C12200 is phosphorus-deoxidized copper (Cu ≥ 99.90%, equivalent to TP2). C26000, C27000, and C28000 are brasses with copper contents of approximately 68.5–71.5%, 64–67%, and 59–62%, roughly corresponding to H70, H66, and H60.

Identification Key: grade prefixes T, TU, and TP denote pure copper, while H denotes brass; the C-series indicates ASTM grades, where grades starting with C1 are typically pure copper and those starting with C2 are typically brass. Alloys with the same composition often correspond to both Chinese National Standards (GB) and ASTM designations — TP2 ≈ C12200 and T2 ≈ C11000.

Temper Designations and Heat Treatment

• M (Soft Temper): fully annealed through soft annealing; high ductility and low strength; suitable for bending, flaring, and deep drawing. Common designations include T2M and H62M.
• M2 (Light Soft): lightly soft-annealed; properties fall between soft and half-hard tempers; commonly used under the GB/T 1527 standard.
• Y2 (Half-Hard): half-hardened by cold working; balances strength and ductility with good structural support. Designations include T2Y2 and H62Y2.
• Y (Hard Temper): hardened by cold working; high strength and rigidity with poorer formability. Designations include T2Y and H62Y.
• O60 (Air Conditioning Tube): soft-annealed temper, a globally recognized designation commonly used in the air conditioning and refrigeration industries, such as TP2 O60.

The Primary Production Process Chain

Copper product manufacturing begins with copper cathode (electrolytic copper) as the raw material and proceeds through smelting and casting, hot working, cold working, heat treatment, and final inspection and packaging. Raw materials carry ≥ 99.95% copper content, qualified scrap may be blended in, and batching is performed according to grade specifications. Smelting and casting takes place in induction or reverberatory furnaces, using continuous casting and rolling or ingot casting; phosphorus-deoxidized copper requires the addition of Cu-P alloy for deoxidation, where controlling oxygen content is critical because incomplete deoxidation risks porosity and hydrogen embrittlement. Hot working heats billets or ingots above the recrystallization temperature, with hot rolling at approximately 800–950°C to break down as-cast dendrites, eliminate porosity, and refine grains. Cold working covers cold rolling for thickness reduction, floating-mandrel or coil drawing for tube forming, and wire drawing; work hardening necessitates alternating annealing steps. Heat treatment restores plasticity through intermediate annealing, then bright annealing or softening annealing establishes the final temper, followed by straightening and cutting to length — annealing parameters directly determine the temper (soft, half-hard, or hard) and grain size. Inspection and packaging covers chemical composition, mechanical properties, electrical conductivity, flaw detection, dimensions, and surface quality, with moisture-proof packaging, warehousing, and mandatory standard-compliant sampling and retention of test reports prior to shipment.

The typical route for copper busbars is: Copper Cathode → Melting → Upward Casting (Rod) → Extrusion → Drawing → Cutting to Length → Inspection → Warehousing.

Key Process Points by Product Form

Copper Plates / Strips: hot rolling (breakdown) → cold rolling → annealing → finishing (slitting / leveling). Control points include thickness tolerance, flatness/shape, absence of surface scratches or indentations, and stamping formability.

Copper Tubes: melting & casting → extrusion or rotary piercing → cold drawing (coil drawing / floating mandrel) → annealing → straightening & finishing. Control points include wall thickness uniformity, inner surface cleanliness, and grain size in the annealed state; air-conditioning tubes also require eddy current testing and hydrogen embrittlement testing.

Copper Busbars / Bus Conductors: copper cathode → melting → upward casting (rod) → extrusion → drawing → cutting to length → inspection. Control points include straightness (e.g., ≤ 0.5 mm/m), electrical conductivity, edge chamfering, and dimensional tolerances.

Copper Wire and Braided Wire / Flexible Connectors control wire diameter tolerance, electrical conductivity, wire breakage rate, flexibility, braid density, contact resistance, and terminal security.

How to Specify a Marine Bronze Plate Inquiry

For copper busbars, pure copper such as TMY/T2 or C11000 is recommended, with electrical conductivity typically ≥ 46 m/(Ω·mm²) at 75°C and straightness verified. When requesting a quote, buyers should specify the four key elements: “Grade + Temper + Cross-section + Standard.” Pricing follows a floating model of “LME/SHFE Copper Price + Processing Fee,” and the pricing cycle and the method used to lock in the price (price-fixing) can be clarified upon request.

Because the referenced grade data describes bronze and cupronickel by their alloying elements — tin, aluminum, or beryllium in bronze and nickel in cupronickel — a marine hardware buyer evaluating plate for biofouling-prone seawater service should confirm the alloying element and composition range of the specific grade, together with the applicable standard, before finalizing the order. Jiangsu Xinxiangsheng Special Steel Co., Ltd. can provide material/quality certificates covering chemical composition, mechanical properties, and electrical conductivity, and upon request issues third-party or commercial inspection reports. That documentation chain is what allows a Southeast Asian procurement team to compare quotations on equal terms and to retain traceable records for future reference.