Refractory Metal Zr 704C
ASTM B752 Grade 704C
Zr 704C is the cast form of tin-alloyed Zr 704 (UNS R60704, ASTM B752 Grade 704C), where Sn and small Fe-Cr additions raise strength over pure-zirconium castings.
Reference datasheet — Zr 704C is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the F condition
Zr 704C tempers and conditions
Zr 704C is supplied in 3 conditions, soft to hard. F is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stress relieved | Choose when residual casting or weld-repair stresses must be removed to minimise stress-corrosion cracking risk in chloride-bearing service. | 275 | 435 | 16 | 180 HB | 2.6 % IACS |
FDefault As fabricated | Standard supply condition for corrosion-service valve bodies and pump casings; meets ASTM B752 Grade 704C minima without further heat treatment. | 300 | 450 | 13 | 190 HB | — |
Hot isostatic pressed | Specify for pressure-containing or fatigue-loaded castings where internal shrinkage porosity must be closed and property scatter reduced. | 310 | 470 | 17 | 188 HB | 2.5 % IACS |
What is Zr 704C?
Zr 704C is the cast form of tin-alloyed Zr 704 (UNS R60704, ASTM B752 Grade 704C), where Sn and small Fe-Cr additions raise strength over pure-zirconium castings. Engineers use it for cast valve and pump components in acid and chloride service, with 300 MPa yield, 450 MPa tensile, 13% elongation, 190 HB (89 HRB) and a corrosion resistance rating of 90. It is supplied as-cast, stress-relieved or HIPed. Elongation and machinability (rated 30) are lower than Zr 702C, service is limited to about 400 °C, and swarf is pyrophoric; choose Zr 702C when ductility and weld repair ease matter more than strength. Zr 704C has a density of 6.56 g/cm³ (0.237 lb/in³), lighter than 71% of refractory metal grades. It melts at 1,800°C (3,272 °F). Zr 704C has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 60% of refractory metal grades. Elongation at break is 13% and the elastic modulus is 99 GPa (14.4 Msi).
What is Zr 704C used for?
- Cast valve bodies
- Pump impellers
- Corrosion-resistant castings
Limitations
- Poor heat conductor — 13 W/m·K (7.51 BTU/hr·ft·°F), worse than 95% of refractory metal grades
- Low electrical conductivity — 2.5 % IACS, worse than 86% of refractory metal grades
- Low stiffness — 99 GPa (14.4 Msi), worse than 79% of refractory metal grades
Zr 704C properties
Typical room-temperature values for Zr 704C-F; bars are the position among refractory metal grades.
Physical3
Zr 704C has a density of 6.56 g/cm³ (0.237 lb/in³), lighter than 71% of refractory metal grades. It melts at 1,800°C (3,272 °F).
Mechanical16
Zr 704C has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 60% of refractory metal grades. Elongation at break is 13% and the elastic modulus is 99 GPa (14.4 Msi).
Thermal6
Zr 704C is rated for continuous service to 400°C (752 °F). It conducts heat at 13 W/m·K (7.51 BTU/hr·ft·°F), worse than 95% of refractory metal grades. Thermal expansion is 6 µm/m·K (3.33 µin/in·°F).
Electrical3
Zr 704C conducts electricity at 2.5 % IACS, worse than 86% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), better than 75% of refractory metal grades.
Sustainability4
Producing a kilogram of Zr 704C takes about 1,200 MJ of energy and emits 75 kg of CO₂ — less than 51% of refractory metal grades. Typical recycled content is 25%.
Manufacturability8
Zr 704C's machinability is poor (30/100, better than 54% of refractory metal grades); weldability good (65/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the refractory metal family
Yield strength against density for every refractory metal grade FabDigit runs. Zr 704C is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Zr 704C
Is Zr 704C easy to machine?
Use slow speeds, heavy positive-rake carbide tooling and flood coolant to avoid galling and work hardening; collect chips wet — fine Zr swarf is pyrophoric.
Can Zr 704C be welded?
GTAW weld repair is routine but must be done with full argon/helium shielding or in a chamber (<50 ppm O2/N2); avoid oxide, oil and hydrogen sources, then stress relieve.
Can Zr 704C be formed, bent or molded?
Vacuum or inert-gas induction melting into graphite or rammed-graphite moulds; generous risers and controlled interstitial pickup are essential, HIP optional to close porosity.
Zr 704C chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Snsolid-solution strengthener | 1 – 2 | 1.5 |
| Fe+Crcombined iron plus chromium per ASTM B752 | 0.2 – 0.4 | 0.3 |
| Hfhafnium not removed (non-nuclear grade) | ≤ 4.5 | |
| Ointerstitial limit; controls ductility | ≤ 0.18 | 0.12 |
| C | ≤ 0.05 | |
| N | ≤ 0.03 | |
| H | ≤ 0.01 | |
| ZrZr + Hf ≥ 97.5 % typical | balance |
What surface finishes work on Zr 704C?
Grit blast plus nitric-hydrofluoric pickle to remove alpha case and mould reaction layer; the self-formed oxide is the working corrosion barrier — no coating or plating required.
Equivalent designations
Standards and trade names that resolve to Refractory Metal Zr 704C in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B752 Grade 704C
- Similar grades
- R60704
How much does Zr 704C cost?
Zr 704C is a high-cost refractory metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Zr 704C — frequently asked
What is Zr 704C used for?
Zr 704C is typically used for cast valve bodies, pump impellers and corrosion-resistant castings. In short: strongest cast Zr grade; sn-alloyed for higher yield; self-forming oxide barrier.
What is the yield strength of Zr 704C?
Zr 704C has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 60% of refractory metal grades. Strength varies by condition: see the 3 listed tempers.
Is Zr 704C easy to machine?
Not especially — machinability is rated poor (30/100, better than 54% of refractory metal grades). Use slow speeds, heavy positive-rake carbide tooling and flood coolant to avoid galling and work hardening; collect chips wet — fine Zr swarf is pyrophoric.
Can Zr 704C be welded?
Yes — weldability is rated good (65/100). GTAW weld repair is routine but must be done with full argon/helium shielding or in a chamber (<50 ppm O2/N2); avoid oxide, oil and hydrogen sources, then stress relieve.
What surface finishes work on Zr 704C?
Grit blast plus nitric-hydrofluoric pickle to remove alpha case and mould reaction layer; the self-formed oxide is the working corrosion barrier — no coating or plating required.
Can Zr 704C be formed, bent or molded?
Vacuum or inert-gas induction melting into graphite or rammed-graphite moulds; generous risers and controlled interstitial pickup are essential, HIP optional to close porosity.
What is the maximum service temperature of Zr 704C?
Zr 704C is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Zr 704C-F and Zr 704C-SR?
F is the default condition — standard supply condition for corrosion-service valve bodies and pump casings; meets ASTM B752 Grade 704C minima without further heat treatment. SR: choose when residual casting or weld-repair stresses must be removed to minimise stress-corrosion cracking risk in chloride-bearing service. Yield strength is 300 MPa in F versus 275 MPa in SR.
How much does Zr 704C cost?
Zr 704C is a high-cost refractory metal ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B752 — Standard Specification for Castings, Zirconium-Base, Corrosion Resistant, for General Application — ASTM International (2020)
- ASTM B551/B550 — Zirconium and Zirconium Alloy Strip, Sheet, Plate, Bar and Wire (Grade R60704) — ASTM International (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Zirconium and Hafnium) — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (Zirconium) — ASM International (2005)
- ATI Zirconium Alloys 702/704/705 technical data — ATI Specialty Materials (2016)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.