Steel 13CrMoSi5-5 +QT (Quenched and tempered)
Heat-treated state
EN 13CrMoSi5-5
Choose for thicker-wall pipe, forged fittings and pressure parts needing higher room-temperature strength and toughness than +NT.
Values for the +QT condition
Other 13CrMoSi5-5 tempers and conditions
13CrMoSi5-5 is listed in 3 conditions; see the grade overview at 13CrMoSi5-5.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition, supplied for heavy machining, cold bending or before final heat treatment of forgings/fittings. | 250 | 450 | 30 | 135 HB | — |
+NTDefault Normalized and tempered | Standard EN 10216-2 / A335 P11 delivery condition for boiler, superheater and process-furnace tubing operating up to ~570 °C. | 290 | 500 | 26 | 150 HB | — |
+QTThis page Quenched and tempered | Choose for thicker-wall pipe, forged fittings and pressure parts needing higher room-temperature strength and toughness than +NT. | 400 | 590 | 22 | 12 HRC | — |
What is 13CrMoSi5-5 +QT?
13CrMoSi5-5 +QT is 13CrMoSi5-5 heat treated to +QT — choose for thicker-wall pipe, forged fittings and pressure parts needing higher room-temperature strength and toughness than +NT. 13CrMoSi5-5 +QT has a yield strength of 400 MPa (58 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 60% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi). 13CrMoSi5-5 +QT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F). +NT is the default condition FabDigit quotes; +QT is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 150 MPa·√m (136.5 ksi·√in), better than 96% of steel grades
- High service temperature — 550°C (1,022 °F), better than 95% of steel grades
13CrMoSi5-5 +QT properties
Typical room-temperature values for 13CrMoSi5-5 +QT; 19 are specific to this condition. Other listed values are 13CrMoSi5-5 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
13CrMoSi5-5 +QT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical16
13CrMoSi5-5 +QT has a yield strength of 400 MPa (58 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 60% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
13CrMoSi5-5 +QT is rated for continuous service to 550°C (1,022 °F). It conducts heat at 39 W/m·K (22.5 BTU/hr·ft·°F), worse than 67% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
13CrMoSi5-5 +QT conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of 13CrMoSi5-5 +QT takes about 31 MJ of energy and emits 2.3 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 25%.
Manufacturability7
13CrMoSi5-5 +QT's machinability is fair (48/100, worse than 57% of steel grades); weldability good (60/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 13CrMoSi5-5 +QT
Is 13CrMoSi5-5 easy to machine?
Machines like a normalized medium-carbon low-alloy steel — carbide tooling, ~55 % of AISI 1212 speeds; slightly gummy in the annealed condition, best surface finish at 150–190 HB.
Can 13CrMoSi5-5 be welded?
Weldable by GTAW/SMAW/SAW with matching 1.25Cr-0.5Mo filler (e.g. ER80S-B2 / E8018-B2); preheat 150–250 °C and PWHT at 700–750 °C to avoid hard HAZ and temper embrittlement.
Can 13CrMoSi5-5 be formed, bent or molded?
Hot form at 950–1150 °C; cold bending of tube is practical to ~3D radius in +A/+NT condition, followed by re-normalizing and tempering for creep service.
What surface finishes work on 13CrMoSi5-5?
No anodizing; protect with aluminizing/chromizing, high-temperature silicone-aluminium paint or phosphate + oil for storage — the Cr/Si only helps against dry high-temperature oxidation.
13CrMoSi5-5 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 |
|---|---|---|
| C | 0.08 – 0.15 | 0.13 |
| Siraised Si for scaling resistance | 0.5 – 1 | 0.7 |
| Mn | 0.4 – 0.7 | 0.55 |
| P | ≤ 0.03 | — |
| S | ≤ 0.02 | — |
| Cr | 1 – 1.5 | 1.25 |
| Mo | 0.45 – 0.65 | 0.55 |
| Fe | balance | — |
13CrMoSi5-5 +QT — frequently asked
What is 13CrMoSi5-5 +QT used for?
13CrMoSi5-5 +QT is typically used for boiler tubes, superheater tubing and pressure piping. In short: better scaling resistance; 1.25Cr-0.5Mo tube steel; rated to 570 °C.
What is the yield strength of 13CrMoSi5-5 +QT?
13CrMoSi5-5 +QT has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is 13CrMoSi5-5 +QT easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% of steel grades). Machines like a normalized medium-carbon low-alloy steel — carbide tooling, ~55 % of AISI 1212 speeds; slightly gummy in the annealed condition, best surface finish at 150–190 HB.
Can 13CrMoSi5-5 +QT be welded?
Yes — weldability is rated good (60/100). Weldable by GTAW/SMAW/SAW with matching 1.25Cr-0.5Mo filler (e.g. ER80S-B2 / E8018-B2); preheat 150–250 °C and PWHT at 700–750 °C to avoid hard HAZ and temper embrittlement.
What surface finishes work on 13CrMoSi5-5 +QT?
No anodizing; protect with aluminizing/chromizing, high-temperature silicone-aluminium paint or phosphate + oil for storage — the Cr/Si only helps against dry high-temperature oxidation.
Can 13CrMoSi5-5 +QT be formed, bent or molded?
Hot form at 950–1150 °C; cold bending of tube is practical to ~3D radius in +A/+NT condition, followed by re-normalizing and tempering for creep service.
What is the maximum service temperature of 13CrMoSi5-5 +QT?
13CrMoSi5-5 +QT is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10216-2 — Seamless steel tubes for pressure purposes, non-alloy and alloy steels with specified elevated temperature properties — CEN (2020)
- ASTM A335/A335M — Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service (Grade P11) — ASTM International (2023)
- DIN 17175 — Seamless tubes of heat-resistant steels (13CrMoSi44 heritage grade) — DIN (1979)
- ASME BPVC Section II Part D — Properties (Metric), 1.25Cr-0.5Mo material data — ASME (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
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.