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Steel ER70S-B2L PWHT-690

Heat-treated state

UNS K20500

Standard condition for ASME code Cr-Mo piping: tempers the weld metal, restores toughness and brings hardness below typical 225 HB / 22 HRC limits.

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Values for the PWHT-690 condition

Other ER70S-B2L tempers and conditions

ER70S-B2L is listed in 3 conditions; see the grade overview at ER70S-B2L.

Compare all 3 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
High-temperature temper 730–760 °C
Use when the fabrication receives repeated or extended PWHT (wet H2S / HTHA service) requiring maximum softening and hardness well under 200 HB.41052028150 HB8.2 % IACS
PWHT-690This page
PWHT
Standard condition for ASME code Cr-Mo piping: tempers the weld metal, restores toughness and brings hardness below typical 225 HB / 22 HRC limits.45056026165 HB—
AWDefault
As-welded deposit
Pick for tack welds, thin-wall or code-exempt joints where PWHT is impractical — the low-carbon B2L chemistry keeps as-welded hardness and cracking risk down.5206202218 HRC—

What is ER70S-B2L PWHT-690?

ER70S-B2L PWHT-690 is ER70S-B2L heat treated to PWHT-690 — standard condition for ASME code Cr-Mo piping: tempers the weld metal, restores toughness and brings hardness below typical 225 HB / 22 HRC limits. ER70S-B2L PWHT-690 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 560 MPa (81.2 ksi) — stronger than 52% of steel grades. Elongation at break is 26% and the elastic modulus is 205 GPa (29.7 Msi). ER70S-B2L PWHT-690 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F). AW is the default condition FabDigit quotes; PWHT-690 is available on request or by drawing note.

Advantages

  • High service temperature — 550°C (1,022 °F), better than 95% of steel grades
  • Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
  • Readily welded — 75/100, better than 76% of steel grades

Limitations

  • High embodied carbon — 2.8 kg CO₂/kg, worse than 90% of steel grades

ER70S-B2L PWHT-690 properties

Typical room-temperature values for ER70S-B2L PWHT-690; 11 are specific to this condition. Other listed values are ER70S-B2L reference data and may not represent this condition. Bars are the position among steel grades.

Physical3

ER70S-B2L PWHT-690 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,490°C (2,714 °F).

Density7.85 g/cm³0.28 lb/in³
Melting Point (Solidus)1,490°C2,714 °F
Liquidus Temperature1,520°C2,768 °F

Mechanical15

ER70S-B2L PWHT-690 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 560 MPa (81.2 ksi) — stronger than 52% of steel grades. Elongation at break is 26% and the elastic modulus is 205 GPa (29.7 Msi).

Elastic (Young's) Modulus205 GPa29.7 Msi
Shear Modulus80 GPa11.6 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.29
Tensile Strength (Ultimate)560 MPa81.2 ksi
Yield Strength (0.2% offset)450 MPa65.3 ksi
Elongation at Break26%
Reduction in Area65%
Shear Strength400 MPa58 ksi
Fatigue Strength (Endurance Limit)250 MPa36.3 ksi
Charpy V-Notch Impact (RT)110 J81.1 ft·lbf
Hardness, Brinell165 HB
Hardness, Rockwell B85 HRB
Hardness, Rockwell C18 HRC
Hardness, Vickers175 HV

Thermal6

ER70S-B2L PWHT-690 is rated for continuous service to 550°C (1,022 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).

Thermal Conductivity42 W/m·K24.3 BTU/hr·ft·°F
Specific Heat Capacity460 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)12.3 µm/m·K6.8 µin/in·°F
Latent Heat of Fusion270 J/g116 BTU/lb
Max Service Temperature (continuous)550°C1,022 °F
Min Service Temperature-30°C-22 °F

Electrical3

ER70S-B2L PWHT-690 conducts electricity at 8 % IACS, better than 55% of steel grades.

Electrical Conductivity8 % IACS
Electrical Resistivity2.2×10⁻⁷ Ω·m8.66 µΩ·in
Magnetic Responseferromagnetic

Chemical & Environmental3

Corrosion resistance is poor (18/100), better than 83% of steel grades.

Galvanic Potential (seawater, vs SCE)-0.6 V
Corrosion ResistancePoor18/100
Chemical Resistance SummaryNot corrosion resistant: rusts in moist air and needs coating or insulation; good resistance to high-temperature hydrogen attack and oxidation up to ~550 °C (Nelson-curve service), poor in acids, chlorides and wet H2S without control of weld hardness.

Sustainability4

Producing a kilogram of ER70S-B2L PWHT-690 takes about 36 MJ of energy and emits 2.8 kg of CO₂ — more than 89% of steel grades. Typical recycled content is 35%.

Embodied Energy (primary production)36 MJ/kg15,477 BTU/lb
Embodied Carbon (primary production)2.8 kg CO₂/kg
Embodied Water60 L/kg7.2 gal/lb
Typical Recycled Content35%

Manufacturability6

ER70S-B2L PWHT-690's machinability is fair (50/100, worse than 53% of steel grades); weldability very good (75/100); formability fair (45/100).

MachinabilityFair50/100
Machinability Rating (AISI 1212 = 100 %)60%
WeldabilityVery good75/100
Formability (cold)Fair45/100
Brazeability / SolderabilityGood60/100
PolishabilityGood55/100

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with ER70S-B2L PWHT-690

Is ER70S-B2L easy to machine?

Machine the deposit after PWHT — as-welded bainitic/martensitic weld metal is abrasive on HSS; use carbide at moderate speed with rigid setup.

Can ER70S-B2L be welded?

GTAW/GMAW of P11/P12 with 150–250 °C preheat, ≤300 °C interpass, dry argon shielding, and PWHT at 690–730 °C; the low-carbon grade tolerates short delays before PWHT better than ER70S-B2.

Can ER70S-B2L be formed, bent or molded?

Supplied only as drawn wire or cut rod; no cold forming of the deposit — bend tests should follow PWHT.

What surface finishes work on ER70S-B2L?

Weld metal rusts readily: grind/blast and prime, or insulate for hot service; no anodizing applicable and plating is rarely used on the joint.

ER70S-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.

ElementSpec limit (wt %)Nominal
Clow-carbon 'L' grade≤ 0.050.04
Mn0.4 – 0.70.55
Si0.4 – 0.70.55
Cr1.2 – 1.51.35
Mo0.4 – 0.650.52
P≤ 0.030.01
S≤ 0.030.01
Cuincluding any copper coating≤ 0.350.15
Febalance—

ER70S-B2L PWHT-690 — frequently asked

What is ER70S-B2L PWHT-690 used for?

ER70S-B2L PWHT-690 is typically used for P11/P12 chrome-moly pipe welding, hydrocracker piping, power generation steam lines and petrochemical process piping. In short: low-carbon Cr-Mo filler; reduced underbead cracking risk; softer as-welded than B2.

What is the yield strength of ER70S-B2L PWHT-690?

ER70S-B2L PWHT-690 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 560 MPa (81.2 ksi) — stronger than 52% of steel grades. Strength varies by condition: see the 3 listed tempers.

Is ER70S-B2L PWHT-690 easy to machine?

Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machine the deposit after PWHT — as-welded bainitic/martensitic weld metal is abrasive on HSS; use carbide at moderate speed with rigid setup.

Can ER70S-B2L PWHT-690 be welded?

Yes — weldability is rated very good (75/100). GTAW/GMAW of P11/P12 with 150–250 °C preheat, ≤300 °C interpass, dry argon shielding, and PWHT at 690–730 °C; the low-carbon grade tolerates short delays before PWHT better than ER70S-B2.

What surface finishes work on ER70S-B2L PWHT-690?

Weld metal rusts readily: grind/blast and prime, or insulate for hot service; no anodizing applicable and plating is rarely used on the joint.

Can ER70S-B2L PWHT-690 be formed, bent or molded?

Supplied only as drawn wire or cut rod; no cold forming of the deposit — bend tests should follow PWHT.

What is the maximum service temperature of ER70S-B2L PWHT-690?

ER70S-B2L PWHT-690 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

  1. AWS A5.28/A5.28M — Low-Alloy Steel Electrodes and Rods for Gas Shielded Arc Welding — American Welding Society (2020)
  2. ASME BPVC Section II Part C / Part D (SFA-5.28; 1.25Cr-0.5Mo physical properties) — ASME (2023)
  3. Chrome-moly solid wire weld-metal property sheets (ER70S-B2L class) — Lincoln Electric / ESAB / Böhler Welding (2023)
  4. ASM Handbook Vol. 6 — Welding, Brazing and Soldering (Cr-Mo steels) — ASM International (1993)

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.