Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) — Copper Grade Specification, Properties & Equivalents

Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) is a high-conductivity copper alloy revered in India for its excellent brazing and welding characteristics, coupled with good corrosion resistance. Unlike OFHC copper, the phosphorus content in DHP copper acts as a deoxidizer during melting, ensuring a cleaner product and preventing hydrogen embrittlement during high-temperature processing like welding or brazing. This makes Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) the material of choice for critical applications in the HVAC industry, including refrigeration tubing and air conditioning lines, as well as in plumbing systems for potable water and potable water distribution. Foundries and specialized component manufacturers across India, particularly in the industrial belts of Pune, Chennai, and Gujarat, rely on Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) for heat exchangers and intricate plumbing fittings where integrity and long-term performance are paramount. Its reliable weldability and resistance to oxidation at elevated temperatures solidify its position as a key copper grade for demanding engineering tasks.

Chemical Composition of Deoxidized High Phosphorus (DHP / Cu-DHP / C12200)

DHP Copper (C12200) Chemical Composition

Mechanical Properties of Deoxidized High Phosphorus (DHP / Cu-DHP / C12200)

DHP Copper (C12200) Mechanical Properties

Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) Copper Available Forms in India

Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) Copper: Real-world Applications

• HVACR: Seamless tubing for refrigeration and air conditioning systems in India.
• Plumbing: Potable water pipes, hot water lines, and distribution networks.
• Heat Exchangers: Components requiring excellent thermal conductivity and corrosion resistance.
• Electrical Connectors: Where high-temperature soldering or brazing is required.
• Automotive: Fuel and brake lines demanding robust joining methods.
• Industrial Piping: For conveying various fluids and gases where brazing is preferred.
• Fire Sprinkler Systems: Corrosion-resistant tubing for safety applications.
• Radiators: Efficient heat transfer components in automotive and industrial use.

Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) Copper: Machinability & Weldability

Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) copper offers good machinability, rating around 80% that of Free Machining Brass (C36000). Its higher phosphorus content, while beneficial for deoxidation, slightly reduces electrical and thermal conductivity compared to pure copper grades like OFHC, but this is often acceptable for its primary applications. Tools made of High-Speed Steel (HSS) or Tungsten Carbide are recommended for machining DHP copper, with speeds typically ranging from 15-30 m/min for turning and 10-20 m/min for drilling, depending on the operation and tool geometry. Generous use of cutting fluids is advised to maintain tool life and achieve a smooth surface finish.

Weldability is a key strength of Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) copper. It exhibits excellent weldability using TIG (GTAW) and MIG (GMAW) processes, often with filler metals like Cu-P alloys or silicon bronze. The phosphorus content effectively prevents the formation of copper oxides during welding, thereby avoiding porosity and ensuring strong, ductile joints. Oxy-acetylene welding is also possible, but care must be taken to minimize overheating. Due to its low melting point and good ductility, post-weld heat treatment is typically not required for Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) copper in most plumbing and HVAC applications, though stress-relieving anneals at around 300-400°C can be performed if necessary for specific service conditions.

Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) Copper: Heat Treatment & Processing

Heat treatment of Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) copper is primarily focused on stress relief or annealing to restore ductility after cold working. Annealing temperatures typically range from 500°C to 750°C, depending on the desired grain size and level of softening. For stress relieving, lower temperatures around 250°C to 400°C for 30-60 minutes are sufficient to reduce internal stresses introduced during fabrication, preventing season cracking without significant loss of strength. Complete recrystallization and softening occur above 500°C.

Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) copper cannot be hardened by heat treatment (i.e., by quenching and tempering) as it does not form martensitic structures. Its mechanical properties are primarily enhanced through cold working. Normalizing is not applicable to copper alloys. The critical aspect of processing Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) copper is ensuring a protective atmosphere or avoiding excessive temperatures during high-temperature brazing or welding to prevent oxidation and maintain the integrity of the deoxidized structure. Careful control of heating and cooling rates during annealing is important to achieve uniform properties throughout the material.

Sourcing Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) Copper in India

Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) copper is widely available from major Indian producers like Hindalco, Vedanta, and Nalco, as well as numerous smaller specialized copper processors and importers. Major stockists and distributors are concentrated in key industrial hubs, with significant availability in Mumbai, Pune, Chennai, and the NCR region. Minimum Order Quantities (MOQs) can vary; for standard tube and pipe sizes, MOQs might range from 100 kg to 500 kg, while for custom forms or smaller quantities, higher MOQs or premium pricing may apply.

The current price band for Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) copper typically falls between INR 650 to 780 per kg, subject to market fluctuations, purity, form, and order volume. Buyers should always specify their requirements for Material Test Certificates (MTC) as per IS 12456 or relevant ASTM standards (e.g., ASTM B111, ASTM B68), including chemical composition and mechanical properties. Third-party inspection and Positive Material Identification (PMI) are often requested by quality-conscious buyers to ensure compliance with specifications. Procuring Deoxidized High Phosphorus (DHP / Cu-DHP / C12200) copper with reliable MTCs is crucial for critical applications.

International Equivalents for DHP Copper (C12200)

FAQs about Deoxidized High Phosphorus (DHP / Cu-DHP / C12200)