ASTM A350 LF2

UNS K03011

ASTM A350 LF2 material

low temp carbon steelflange / forgingP-No. 1 / Gr. 2

⚡

Key Engineering Metrics

Instant specifications summary for ASTM A350 LF2

Yield Strength💪

-MPa

Min specified

Tensile Strength🏋️

-MPa

Ultimate min

Carbon Eq. (CE)🧪

0.678

High Cracking Risk

P-No. / Group⚙️

P1 / Gr2

ASME Sec. IX

Flange Group🛡️

Grp 1.1

ASME B16.5

MDMT Curve❄️

Refer to

ASME B31.3

General Specifications & Standard Data

ASTM A350

Standard Specification

ASTM A350

Grade / Designation

LF2

UNS Designation

K03011

ASME P-No. / Group No.

P-No. 1 / Group 2

ASME B31.3 MDMT Curve

Refer to ASME B31.3 Fig 323.2.2A

Minimum Design Metal Temperature rules for impact testing exemption under ASME B31.3 paragraph 323.2.2.

Mechanical Properties

Room Temp (20°C / 68°F)

Density

7850kg/m³

Min Yield

-MPa

Min Tensile

-MPa

Elastic Modulus

200GPa

Thermal Expansion

12µm/m·K

Thermal Cond.

52W/m·K

Poisson’s Ratio

0.3

Allowable Stress Data (ASME B31.3 Table A-1)

asme-bpvc

Allowable Stress vs Temperature

ASME B31.3 / BPVC Section II Part D Reference Curve

Max: 137.9 MPaRange: 38° - 500°

Temperature (°C)	Allowable Stress (MPa)	% of Room Temp Rating
38	137.9	100%
100	137.9	100%
150	137.9	100%
200	137.9	100%
250	135.8	99%
300	128.9	94%
350	122.0	88%
400	101.4	74%
450	66.9	48%
500	34.5	25%
550	–	–
600	–	–
650	–	–

🛡️ ASME B16.5 Flange P-T Ratings & Calculator

Material Group 1.1 (Carbon and low-alloy steel materials)

bar / °C

Rating Class: Class 150

Max Allowable Pressure19.6 bar

Design Temp (°C):

Code Limit: -29° to 538°

Temp (°C)	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
-29 to 38	19.6	51.1	68.1	102.1	153.2	255.3	425.5
50	19.2	50.1	66.8	100.2	150.4	250.6	417.7
100	17.7	46.6	62.1	93.2	139.8	233	388.3
150	15.8	45.1	60.1	90.2	135.2	225.4	375.6
200	13.8	43.8	58.4	87.6	131.4	219	365
250	12.1	41.9	55.9	83.9	125.8	209.7	349.5
300	10.2	39.8	53.1	79.6	119.5	199.1	331.8
325	9.3	38.7	51.6	77.4	116.1	193.6	322.6
350	8.4	37.6	50.1	75.1	112.7	187.8	313
375	7.4	36.4	48.5	72.7	109.1	181.8	303.1
400	6.5	34.7	46.3	69.4	104.2	173.6	289.3
425	5.5	28.8	38.4	57.5	86.3	143.8	239.7
450	4.6	23	30.7	46	69	115	191.7
475	3.7	17.4	23.2	34.9	52.3	87.2	145.3
500	2.8	11.8	15.7	23.5	35.3	58.8	97.9
538	1.4	5.9	7.9	11.8	17.7	29.5	49.2

Working pressures are in gauge (bar). Values interpolated linearly for intermediate temperatures per ASME B16.5 para. 2.3.

Chemical Composition (% Weight)

Heat & Product Analysis

Carbon Equivalent (CE - IIW Formula)

CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15

Preheat and strict PWHT required

0.678

High Cracking Risk

≤ 0.3%

0.6–1.35%

0.15–0.3%

≤ 0.035%

≤ 0.04%

≤ 0.3%

≤ 0.4%

≤ 0.12%

≤ 0.4%

≤ 0.08%

≤ 0.02%

🛡️ Service Compatibility

Refrigerated Gas & Cold Fluidexcellent

Impact tested down to -45°C (-50°F). Standard for LPG, cold hydrocarbons & cold climates.

Hydrocarbon Processexcellent

Ideal for low-temp oil & gas process lines.

Steam & Hot Processgood

Suitable for steam & process up to 343°C (650°F).

Sour Service (H2S)check

Requires NACE MR0175 compliance and controlled hardness ≤22 HRC.

Cryogenic LNG ( 162°C)not-recommended

Limited to -45°C. For LNG (-162°C), use Austenitic Stainless Steel (304L/316L).

🔥 Welding & Heat Treatment

Weldabilitymoderate

Preheat Requirements

10°C min; 95°C for t > 19mm. Maintain interpass temp ≤ 230°C to preserve low-temperature notch toughness.

PWHT Requirements

Required for nominal wall thickness t > 19mm (holding temp 590°C–630°C per ASME B31.3).

Charpy Impact Test (CVN)

Mandatory Charpy V-notch impact testing at -45°C (-50°F) for base metal, HAZ, and weld deposit per ASTM A333.

🔗 Material Equivalents

Low Temperature Carbon Steel Service

Pipe: ASTM A333 Gr.6

Flange: ASTM A350 LF2

Fitting: ASTM A420 WPL6

⚠️ Engineering Verification Notice

Material property data provided is for preliminary engineering reference. Always verify properties against the latest ASME BPVC Section II, ASTM material specification, and Material Test Report (MTR/MTC).