Refractory Metal Cr99.90 EL-DEG
Heat-treated state
EL-DEG = vacuum-degassed (low-hydrogen) electrolytic chromium
Choose when melt hydrogen or gas porosity matters — vacuum induction melted superalloys, VIM/VAR steels and Ni-base master alloys; H typically <30 ppm, O reduced.
Values for the EL-DEG condition
What is Cr99.90 EL-DEG?
Cr99.90 EL-DEG is Cr99.90 heat treated to EL-DEG — choose when melt hydrogen or gas porosity matters — vacuum induction melted superalloys, VIM/VAR steels and Ni-base master alloys; H typically <30 ppm, O reduced. Cr99.90 EL-DEG has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 68% of refractory metal grades. Elongation at break is 0% and the elastic modulus is 279 GPa (40.5 Msi). Cr99.90 EL-DEG has a density of 7.19 g/cm³ (0.26 lb/in³), lighter than 57% of refractory metal grades. It melts at 1,907°C (3,465 °F).
Advantages
- Polishes to a fine finish — 80/100, better than 97% of refractory metal grades
- Low embodied carbon — 16 kg CO₂/kg, better than 84% of refractory metal grades
Limitations
- Limited ductility — 0%, worse than 99% of refractory metal grades
- Difficult to weld — 8/100, worse than 97% of refractory metal grades
- Limited formability — 3/100, worse than 96% of refractory metal grades
- Difficult to machine — 6/100, worse than 94% of refractory metal grades
- Low fracture toughness — 15 MPa·√m (13.7 ksi·√in), worse than 75% of refractory metal grades
Cr99.90 EL-DEG properties
Typical room-temperature values for Cr99.90 EL-DEG; 4 are specific to this condition. Other listed values are Cr99.90 reference data and may not represent this condition. Bars are the position among refractory metal grades.
Physical3
Cr99.90 EL-DEG has a density of 7.19 g/cm³ (0.26 lb/in³), lighter than 57% of refractory metal grades. It melts at 1,907°C (3,465 °F).
Mechanical11
Cr99.90 EL-DEG has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 68% of refractory metal grades. Elongation at break is 0% and the elastic modulus is 279 GPa (40.5 Msi).
Thermal5
Cr99.90 EL-DEG is rated for continuous service to 900°C (1,652 °F). It conducts heat at 93.9 W/m·K (54.3 BTU/hr·ft·°F), better than 74% of refractory metal grades. Thermal expansion is 4.9 µm/m·K (2.72 µin/in·°F).
Electrical3
Cr99.90 EL-DEG conducts electricity at 13.8 % IACS, better than 73% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 52% of refractory metal grades.
Sustainability4
Producing a kilogram of Cr99.90 EL-DEG takes about 190 MJ of energy and emits 16 kg of CO₂ — less than 87% of refractory metal grades. Typical recycled content is 2%.
Manufacturability7
Cr99.90 EL-DEG's machinability is not recommended (6/100, worse than 94% of refractory metal grades); weldability not recommended (8/100); formability not recommended (3/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Cr99.90 EL-DEG
Is Cr99.90 easy to machine?
Effectively non-machinable in the as-deposited state — brittle and very hard; consolidated bar can only be ground, EDM'd or diamond-sawn with ample coolant.
Can Cr99.90 be welded?
Poor: welds crack because chromium is brittle below ~150 °C and picks up N/H/O readily — inert-gas or vacuum processes with preheat only, and only on consolidated material.
Can Cr99.90 be formed, bent or molded?
No cold forming; any deformation processing must be done hot (typically >300–500 °C, often canned in steel) above the ductile–brittle transition.
What surface finishes work on Cr99.90?
Not anodised; the natural Cr₂O₃ film gives bright, stable surfaces — polish or lightly etch for targets, and keep flake dry to avoid fines oxidation.
Cr99.90 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 |
|---|---|---|
| Fe | ≤ 0.03 | 0.02 |
| Si | ≤ 0.02 | 0.01 |
| Al | ≤ 0.01 | 0 |
| C | ≤ 0.01 | 0 |
| S | ≤ 0.01 | 0 |
| P | ≤ 0.01 | 0 |
| O | ≤ 0.05 | 0.03 |
| N | ≤ 0.01 | 0 |
| Hnon-dehydrogenated electrolytic flake; dehydrogenated ≤ 0.003 % | ≤ 0.05 | 0.03 |
| Cu | ≤ 0.01 | 0 |
| Crcalculated by difference | ≥ 99.9 (balance) |
Cr99.90 EL-DEG — frequently asked
What is Cr99.90 EL-DEG used for?
Cr99.90 EL-DEG is typically used for superalloy master alloy addition, stainless steel alloying, vacuum melting charge material, chromium plating anodes and research/high-purity metallurgy. In short: highest-purity chromium source; brittle below ~150 °C; melt addition, not a part.
What is the yield strength of Cr99.90 EL-DEG?
Cr99.90 EL-DEG has a typical yield strength of 260 MPa (37.7 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 68% of refractory metal grades.
Is Cr99.90 EL-DEG easy to machine?
Not especially — machinability is rated not recommended (6/100, worse than 94% of refractory metal grades). Effectively non-machinable in the as-deposited state — brittle and very hard; consolidated bar can only be ground, EDM'd or diamond-sawn with ample coolant.
Can Cr99.90 EL-DEG be welded?
Not readily — weldability is rated not recommended (8/100). Poor: welds crack because chromium is brittle below ~150 °C and picks up N/H/O readily — inert-gas or vacuum processes with preheat only, and only on consolidated material.
What surface finishes work on Cr99.90 EL-DEG?
Not anodised; the natural Cr₂O₃ film gives bright, stable surfaces — polish or lightly etch for targets, and keep flake dry to avoid fines oxidation.
Can Cr99.90 EL-DEG be formed, bent or molded?
No cold forming; any deformation processing must be done hot (typically >300–500 °C, often canned in steel) above the ductile–brittle transition.
What is the maximum service temperature of Cr99.90 EL-DEG?
Cr99.90 EL-DEG is rated for continuous use to about 900°C (1,652 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- GB/T 3211 (2008)
- ASTM A481 Standard Specification for Chromium Metal — ASTM International (2018)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- CRC Handbook of Chemistry and Physics, Physical Constants of the Elements — CRC Press (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.