Steel E70C-B2L PWHT-705LT
Heat-treated state
UNS W52130
PWHT-705LT = pWHT-LT
Condition after repeated or extended stress-relief cycles typical of heavy vessel fabrication; strength drops toward the specification minimum, so check that design allowables are still met.
Values for the PWHT-705LT condition
Other E70C-B2L tempers and conditions
E70C-B2L is listed in 3 conditions; see the grade overview at E70C-B2L.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
PWHT-705LTThis page PWHT-LT | Condition after repeated or extended stress-relief cycles typical of heavy vessel fabrication; strength drops toward the specification minimum, so check that design allowables are still met. | 410 | 510 | 28 | 155 HB | 7.9 % IACS |
PWHT-690Default PWHT | Standard supply/qualification condition for code Cr-Mo piping and vessel welds; gives the classified 490 MPa-class properties with low hardness for wet-H₂S or amine service. | 455 | 550 | 25 | 170 HB | — |
As-welded deposit | Use for temporary joints, small non-code repairs or when hardness/strength in the untempered bainitic condition is acceptable; not the AWS classification test condition. | 560 | 660 | 20 | 20 HRC | — |
What is E70C-B2L PWHT-705LT?
E70C-B2L PWHT-705LT is E70C-B2L heat treated to PWHT-705LT — condition after repeated or extended stress-relief cycles typical of heavy vessel fabrication; strength drops toward the specification minimum, so check that design allowables are still met. E70C-B2L PWHT-705LT has a yield strength of 410 MPa (59.5 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 57% of steel grades. Elongation at break is 28% and the elastic modulus is 205 GPa (29.7 Msi). E70C-B2L PWHT-705LT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,470°C (2,678 °F). PWHT-690 is the default condition FabDigit quotes; PWHT-705LT is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 145 MPa·√m (132 ksi·√in), better than 95% of steel grades
- High service temperature — 540°C (1,004 °F), better than 93% of steel grades
- Ductile — tolerates forming and impact — 28%, better than 89% of steel grades
- Readily welded — 78/100, better than 78% of steel grades
Limitations
- High embodied carbon — 2.6 kg CO₂/kg, worse than 87% of steel grades
E70C-B2L PWHT-705LT properties
Typical room-temperature values for E70C-B2L PWHT-705LT; 22 are specific to this condition. Other listed values are E70C-B2L reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
E70C-B2L PWHT-705LT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,470°C (2,678 °F).
Mechanical15
E70C-B2L PWHT-705LT has a yield strength of 410 MPa (59.5 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 57% of steel grades. Elongation at break is 28% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
E70C-B2L PWHT-705LT is rated for continuous service to 540°C (1,004 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.4 µm/m·K (6.89 µin/in·°F).
Electrical3
E70C-B2L PWHT-705LT conducts electricity at 7.9 % IACS, better than 50% of steel grades.
Chemical & Environmental2
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of E70C-B2L PWHT-705LT takes about 34 MJ of energy and emits 2.6 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability6
E70C-B2L PWHT-705LT's machinability is good (60/100, better than 83% of steel grades); weldability very good (78/100); formability fair (50/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E70C-B2L PWHT-705LT
Is E70C-B2L easy to machine?
Machine weld caps after PWHT (~170 HB) with carbide tooling; as-welded bainitic deposits are harder and abrasive on HSS.
Can E70C-B2L be welded?
GMAW/FCAW with Ar-CO₂ (75–80/20–25) or CO₂, DCEP; preheat 150–250 °C, interpass ≤ 300 °C, and PWHT at 675–705 °C for code work — keep hydrogen low and store wire dry.
Can E70C-B2L be formed, bent or molded?
Not a formable product; deposit is applied as weld metal — control bead sequence and heat input to limit distortion and coarse-grain HAZ.
What surface finishes work on E70C-B2L?
Grind/blast and coat or insulate; the deposit rusts like plain steel at ambient temperature and takes no protective oxide below service temperature.
E70C-B2L 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 |
|---|---|---|
| CL = low carbon grade, weld-metal analysis | ≤ 0.05 | 0.04 |
| Mn | ≤ 1.25 | 0.9 |
| Si | ≤ 0.8 | 0.45 |
| Cr | 1 – 1.5 | 1.25 |
| Mo | 0.4 – 0.65 | 0.52 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.03 | 0.01 |
| Niresidual, some specs limit for Cr-Mo service | ≤ 0.2 | 0.05 |
| Curesidual | ≤ 0.35 | 0.05 |
| Vresidual | ≤ 0.05 | 0.01 |
| Fe | balance | — |
E70C-B2L PWHT-705LT — frequently asked
What is E70C-B2L PWHT-705LT used for?
E70C-B2L PWHT-705LT is typically used for 1.25Cr-0.5Mo pipe welding, refinery pressure vessels, power plant piping and petrochemical reactors. In short: low-carbon Cr-Mo deposit; lower as-welded hardness; code PWHT piping filler.
What is the yield strength of E70C-B2L PWHT-705LT?
E70C-B2L PWHT-705LT has a typical yield strength of 410 MPa (59.5 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 57% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is E70C-B2L PWHT-705LT easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machine weld caps after PWHT (~170 HB) with carbide tooling; as-welded bainitic deposits are harder and abrasive on HSS.
Can E70C-B2L PWHT-705LT be welded?
Yes — weldability is rated very good (78/100). GMAW/FCAW with Ar-CO₂ (75–80/20–25) or CO₂, DCEP; preheat 150–250 °C, interpass ≤ 300 °C, and PWHT at 675–705 °C for code work — keep hydrogen low and store wire dry.
What surface finishes work on E70C-B2L PWHT-705LT?
Grind/blast and coat or insulate; the deposit rusts like plain steel at ambient temperature and takes no protective oxide below service temperature.
Can E70C-B2L PWHT-705LT be formed, bent or molded?
Not a formable product; deposit is applied as weld metal — control bead sequence and heat input to limit distortion and coarse-grain HAZ.
What is the maximum service temperature of E70C-B2L PWHT-705LT?
E70C-B2L PWHT-705LT is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between E70C-B2L PWHT-690 and E70C-B2L-AW?
PWHT-690 is the default condition — standard supply/qualification condition for code Cr-Mo piping and vessel welds; gives the classified 490 MPa-class properties with low hardness for wet-H₂S or amine service. AW: use for temporary joints, small non-code repairs or when hardness/strength in the untempered bainitic condition is acceptable; not the AWS classification test condition. Yield strength is 455 MPa in PWHT-690 versus 560 MPa in AW.
Sources
- AWS A5.29/A5.29M — Low-Alloy Steel Electrodes for Flux Cored Arc Welding — American Welding Society (2010)
- ASME BPVC Section II Part C / Part D (SFA-5.29; 1.25Cr-0.5Mo material properties) — ASME (2023)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (Cr-Mo steel weld metals) — ASM International (1993)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Cr-Mo metal-cored/flux-cored wire datasheets (Lincoln, ESAB, Böhler, Kobelco B2L class) — various producers (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.