C12200 is a typical high-phosphorus deoxidized copper in the ASTM standard, through the addition of higher phosphorus content (0.015%-0.040%) to achieve complete deoxidization, significantly improve corrosion resistance and welding performance, while taking into account the electrical conductivity, belonging to the high processability of corrosion-resistant copper. It is widely used in construction piping, heating, ventilation and air conditioning (HVAC) systems and marine engineering, especially for frequent welding or exposure to corrosive media.
The following is a multi-dimensional analysis:
1. Brand and standard
ASTM standard: C12200 (ASTM B152/B133), categorized as high-phosphorus deoxidized copper (DHP copper), corresponding to UNS No. C12200.
Domestic corresponding grade: TP2 (GB/T 5231-2012, phosphorus content 0.015%-0.040%).
International comparison:
EN: Cu-DHP (EN 1652, phosphorus content 0.013%-0.050%);
JIS: C1220 (0.015%-0.040% phosphorus content);
DIN: Cu-DHP (DIN 17650).
2. Chemical composition
Element Content range Description
Copper (Cu) ≥99.85% Matrix, dominant electrical/thermal conductivity
Phosphorus (P) 0.015%-0.040% Strong deoxidization, enhance hydrogen embrittlement and corrosion resistance
Oxygen (O) ≤0.007% Residual oxygen is further reduced to avoid embrittlement of grain boundaries.
Other impurities ≤0.15% (e.g. Fe, Pb) Strict control of impurities to ensure the purity of the material.
3. Core properties
Corrosion resistance:
Anti-dezincification corrosion (seawater environment corrosion rate is 50% lower than pure copper);
Stress Corrosion Cracking (SCC) resistance is very strong, suitable for high-pressure pipelines.
Conductivity:
Annealed state: ≥96% IACS (phosphorus has a controlled effect on conductivity);
Cold-worked state: conductivity decreases by about 3%-5% (still maintains ≥92% IACS).
Processing performance:
Cold rolled deformation rate of up to 70% without cracking, suitable for deep drawing and pipe bending;
Excellent welding performance (brazing, TIG welding without additional deoxidizing treatment).
Mechanical properties:
Annealed state: tensile strength 220-260 MPa, elongation ≥35%;
Hard state: tensile strength 400-480 MPa (cold rolled deformation rate ≥60%).
4. Comparison with similar high phosphorus copper (C12200 vs C11700)
Characteristics C12200 (ASTM high phosphorus) C11700 (ASTM conventional phosphorus)
Phosphorus content 0.015%-0.040% 0.015%-0.040% (same range)
Oxygen Residual Control ≤0.007% ≤0.005%
Corrosion resistance Better (high phosphorus inhibits grain boundary corrosion) Good
Typical applications Desalination pipes, gas valves Building roofs, heat exchanger pipes
5. Areas of application
Piping systems:
Building hot and cold water pipes (ASTM B88 standard, pressure resistance ≥ 2.5 MPa);
Ship seawater cooling pipes (salt spray corrosion resistance life>20 years).
Heating, ventilation and air conditioning (HVAC):
Refrigerant transportation tube (Freon corrosion resistance);
Heat exchanger finned tube (excellent brazing performance).
Energy chemical:
Natural gas pressure reducing valve body (resistant to hydrogen sulfide corrosion);
Geothermal well casing (resistance to corrosion by high temperature geothermal water).
Decorative engineering:
Antique copper tile (surface oxidation treatment showing green rust effect);
Art casting parts (high phosphorus to improve casting fluidity).
