Steel 20R-HIC
Certified grade
HIC = low-sulphur, Ca-treated HIC/wet-H₂S resistant plate
Choose for wet H₂S / sour service; S ≤ 0.003 %, inclusion-shape controlled and NACE TM0284 tested.
Values for the HIC condition
Other 20R tempers and conditions
20R is listed in 5 conditions; see the grade overview at 20R.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Normalized then stress-relieved / simulated PWHT | Condition for thick or heavily welded vessels requiring PWHT; slight strength drop must be allowed in design. | 255 | 445 | 33 | 120 HB | 10.8 % IACS |
Normalized | Mandatory for plate over ~36 mm and preferred where uniform fine grain and better low-temperature toughness are needed. | 265 | 455 | 32 | 125 HB | — |
HICThis page Low-sulphur, Ca-treated HIC/wet-H₂S resistant plate | Choose for wet H₂S / sour service; S ≤ 0.003 %, inclusion-shape controlled and NACE TM0284 tested. | 265 | 450 | 33 | 125 HB | 10.8 % IACS |
ARDefault As hot-rolled plate | Standard stock condition for thin/medium 20R–Q245R vessel plate where no normalizing is required. | 275 | 460 | 30 | 130 HB | 10.8 % IACS |
Thermomechanically controlled processed | Controlled-rolled plate giving normalized-like fine grain without a separate furnace cycle; good toughness with lower carbon equivalent. | 290 | 470 | 32 | 130 HB | 10.8 % IACS |
What is 20R-HIC?
20R-HIC is 20R in a HIC certified grade — choose for wet H₂S / sour service; S ≤ 0.003 %, inclusion-shape controlled and NACE TM0284 tested. 20R-HIC has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 92% of steel grades. Elongation at break is 33% and the elastic modulus is 206 GPa (29.9 Msi). 20R-HIC has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,460°C (2,660 °F). AR is the default condition FabDigit quotes; HIC is available on request or by drawing note.
Advantages
- Readily welded — 96/100, better than 100% of steel grades
- Tough — resists crack growth — 185 MPa·√m (168.4 ksi·√in), better than 99% of steel grades
- Ductile — tolerates forming and impact — 33%, better than 96% of steel grades
- Forms and bends easily — 85/100, better than 96% of steel grades
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
Limitations
- Low strength — 265 MPa (38.4 ksi), worse than 92% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
20R-HIC properties
Typical room-temperature values for 20R-HIC; 22 are specific to this condition. Other listed values are 20R reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
20R-HIC has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,460°C (2,660 °F).
Mechanical16
20R-HIC has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 92% of steel grades. Elongation at break is 33% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
20R-HIC is rated for continuous service to 425°C (797 °F). It conducts heat at 51 W/m·K (29.5 BTU/hr·ft·°F), better than 92% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
20R-HIC conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of 20R-HIC takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability6
20R-HIC's machinability is good (60/100, better than 83% of steel grades); weldability excellent (96/100); formability excellent (85/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 20R-HIC
Is 20R easy to machine?
Machines like mild steel at ~65 % of AISI 1212; gummy chips in the as-rolled state, so use positive rake, good chip breakers and generous coolant.
Can 20R be welded?
Excellent weldability with CEV ≈ 0.35 — SMAW/SAW/GMAW with E7018 or F7A2-EM12K class consumables; preheat 100–150 °C above ~40 mm and PWHT at 600–640 °C per GB 150 when required.
Can 20R be formed, bent or molded?
Cold bends to 1.5×t radius; hot forming of heads at 900–1000 °C should be followed by normalizing if the finishing temperature is uncontrolled.
What surface finishes work on 20R?
No inherent corrosion resistance — shot-blast to Sa2½ and epoxy/zinc-rich prime, or use cladding/weld overlay/internal lining for wet service.
20R 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 |
|---|---|---|
| CGB/T 713 Q245R ≤0.20 | ≤ 0.2 | 0.17 |
| Si | ≤ 0.35 | 0.25 |
| Mn | 0.5 – 1 | 0.8 |
| P | ≤ 0.03 | 0.02 |
| S≤0.003 for HIC grade | ≤ 0.01 | 0.01 |
| Crresidual | ≤ 0.3 | 0.05 |
| Niresidual | ≤ 0.3 | 0.05 |
| Curesidual | ≤ 0.3 | 0.05 |
| Moresidual | ≤ 0.08 | 0.01 |
| Alsacid-soluble Al, fine-grain practice | ≥ 0.02 | 0.03 |
| Fe | balance | — |
20R-HIC — frequently asked
What is 20R-HIC used for?
20R-HIC is typically used for pressure vessel shells, storage tanks and process vessels. In short: workhorse vessel plate; HIC and Z35 options; best-value weldable plate.
What is the yield strength of 20R-HIC?
20R-HIC has a typical yield strength of 265 MPa (38.4 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 92% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is 20R-HIC easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machines like mild steel at ~65 % of AISI 1212; gummy chips in the as-rolled state, so use positive rake, good chip breakers and generous coolant.
Can 20R-HIC be welded?
Yes — weldability is rated excellent (96/100). Excellent weldability with CEV ≈ 0.35 — SMAW/SAW/GMAW with E7018 or F7A2-EM12K class consumables; preheat 100–150 °C above ~40 mm and PWHT at 600–640 °C per GB 150 when required.
What surface finishes work on 20R-HIC?
No inherent corrosion resistance — shot-blast to Sa2½ and epoxy/zinc-rich prime, or use cladding/weld overlay/internal lining for wet service.
Can 20R-HIC be formed, bent or molded?
Cold bends to 1.5×t radius; hot forming of heads at 900–1000 °C should be followed by normalizing if the finishing temperature is uncontrolled.
What is the maximum service temperature of 20R-HIC?
20R-HIC is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 20R-AR and 20R TMCP?
AR is the default condition — standard stock condition for thin/medium 20R–Q245R vessel plate where no normalizing is required. TMCP: controlled-rolled plate giving normalized-like fine grain without a separate furnace cycle; good toughness with lower carbon equivalent. Yield strength is 275 MPa in AR versus 290 MPa in TMCP.
Sources
- GB 6654 (20R, superseded) (1996)
- ASTM A516/A516M Pressure Vessel Plates, Carbon Steel — ASTM International (2021)
- ASM Handbook Vol.1 Properties and Selection: Irons, Steels — ASM International (1990)
- ASME BPVC Section II Part D — material properties tables — ASME (2023)
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.