Nickel Alloy: Monel 400 (UNS N04400)

UNS N04400 or DIN W.Nr. 2.4360 / 2.4361, Monel 400 (also known as “Alloy 400”) is a solid-solution nickel-copper alloy with high strength and excellent resistance in a range of media, including seawater, hydrofluoric acid, sulfuric acid and alkalies. The Alloy 400 is also very resistant to stress-corrosion cracking and pitting corrosion in most fresh and industrial waters. Monel 400 is widely used in many fields such as marine engineering, chemical and hydrocarbon processing equipment, valves, pumps, shafts, flanges, fittings, fasteners, and heat exchangers.

Contents:

• Chemical Analysis
• Typical Physical Properties
• Mechanical Properties
• Yield Strength – Temperature Chart
• Tensile Strength – Temperature Table
• Weldability, Workability & Heat Treatment
• Modulus of Elasticity
• Thermal Conductivity & Thermal Diffusivity
• Thermal Expansion Properties
• Allowable Stress – Temperature
• Product Forms and Standards

1. Monel 400 Ring
2. ASTM B163 Monel 400 Seamless Tube
3. ASTM B165 UNS N04400(Monel 400) Seamless Pipe & Tube
4. Monel 400 Flanges
5. ASME B16.5 Class 150 Flange

• Analysis on Ductility and Fracture
• Elevated Temperatures
• High-Temperature Tension Test Procedures
• ERNiCu-7 Filler Metal for Welding

1. Chemical Composition Requirements of Monel 400

The Chemical Composition of Monel 400, %
Nickel	≥63.0
Carbon	≤0.30
Manganese	≤2.0
Iron	≤2.50
Sulfur	≤0.024
Silicon	≤0.50
Copper	28.0-34.0

2. Typical Physical Properties

Density		Melting Range		Curie Temperature		Electrisity Resistivity
g/cm3	lb/in3	°F	°C	°F	°C	µΩ·m
8.80	0.318	2370-2460	1300-1350	70-120	21-49	547

3. Mechanical Properties of Monel 400

Tensile Strength, min.		Yield Strength, min.		Elongation, min	Hardness
Mpa	ksi	Mpa	ksi	%	HB
550	80	240	35	40	110-150

4. Yield Strength – Temperature Chart of Monel 400

1). Yield Strength – Temperature for Monel 400 Group A

Temperature, °F	-20~100	150	200	250	300	350	400	450	500
Yield Strength, ksi	25.0	23.0	21.9	21.0	20.4	20.0	19.7	19.7	19.7
Temperature, °F	550	600	650	700	750	800	850	900	950
Yield Strength, ksi	19.7	19.7	19.7	19.6	19.4	19.1	18.9	18.8	–

*The “Temperature” shall be interpreted as “not exceeding”.
*Group A includes Monel 400(UNS N04400) materials:(1)bar of ASME SB164, annealed; (2)seamless pipe & tube of ASME SB165, annealed, with O.D＞5″; (3)ASTM B564 forgings, annealed.

2). Yield Strength – Temperature for Monel 400 Group B

Temperature, °F	-20~100	150	200	250	300	350	400	450	500
Yield Strength, ksi	28.0	25.8	24.5	23.6	22.8	22.4	22.1	22.0	22.0
Temperature, °F	550	600	650	700	750	800	850	900	950
Yield Strength, ksi	22.0	22.0	22.0	21.9	21.7	21.4	21.2	21.1	–

*The “Temperature” shall be interpreted as “not exceeding”.
*Group B includes Monel 400(UNS N04400) materials:(1)plate of ASME B127, annealed; (2)seamless tube of ASME SB-163, O.D＜3″ annealed; (3)ASME SB165 seamless pipe & tube with O.D≤5″, annealed; (4)seamless and welded fittings of ASME SB-366, annealed.

3). Yield Strength – Temperature for Monel 400 Group C

Temperature, °F	-20~100	150	200	250	300	350	400	450	500
Yield Strength, ksi	40.0	39.5	38.8	37.9	37.1	36.4	35.9	35.5	35.2
Temperature, °F	550	600	650	700	750	800	850	900	950
Yield Strength, ksi	34.9	34.7	34.4	34.0	33.5	32.9	32.3	31.6	–

*The “Temperature” shall be interpreted as “not exceeding”.
*Group C includes Monel 400(UNS N04400) materials: (1)plate of ASME SB127, as-rolled & tempered condition; (2)hot-rolled round bar of ASME SB-164, O.D≤14″.

4). Yield Strength – Temperature for Monel 400 Group D

Temperature, °F	-20~100	200	300	400	500	600	650	700	750	800
Yield Strength, ksi, D1	50.0	47.2	45.8	45.0	45.0	44.2	42.1	42.1	41.8	40.4
Yield Strength, ksi, D2	55.0	51.8	50.4	49.7	49.2	48.1	47.3	46.3	45.3	44.4
Yield Strength, ksi, D3	60.0	56.6	54.9	54.0	54.0	53.0	50.5	50.5	50.1	48.5
Yield Strength, ksi, D4	85.0	80.2	77.8	76.5	76.5	75.1	71.6	71.6	71.0	68.7

*The “Temperature” shall be interpreted as “not exceeding”.
*Group D includes Monel 400(UNS N04400) materials: D₁-round bar of ASME SB-164, cold rolled & stress relieved, O.D＜0.5″; D₂-round bar of ASME SB-164, cold rolled & stress relieved, 3.5″<O.D≤4″; D₃-round bar of ASME SB-164, cold rolled & stress relieved, 0.5″≤O.D≤3.5″; D₄-round bar of ASME SB-164, cold rolled & tempered, O.D<0.5″.

5). Yield Strength – Temperature for Monel 400 Group E

Temperature, °F	-20~100	150	200	250	300	350	400	450
Yield Strength, ksi	55.0	52.9	51.8	51.0	50.4	50.0	49.7	49.5
Temperature, °F	500	550	600	650	700	750	800	850
Yield Strength, ksi	49.2	48.7	48.1	47.3	46.3	45.3	44.4	–

*The “Temperature” shall be interpreted as “not exceeding”.
*Group E includes Monel 400(UNS N04400) materials: (1)ASTM B163 seamless tube, stress relieved; (2)ASTM B165 seamless pipe & tube, stress relieved.

5. Tensile Strength – Temperature Table for Monel 400 of Different Forms

1). Tensile Strength – Temperature Table for Monel 400 Group A

Temperature	-20~100	200	300	400	500	600	650
Tensile Strength	70.0	70.0	70.0	70.0	70.0	70.0	70.0
Temperature	700	750	800	850	900	950	1000
Tensile Strength	69.7	67.3	64.1	60.3	56.4	52.9	50.5

*The unit of temperature: °F, not exceeding; the unit of tensile strength: ksi.
*Group A refers to Monel 400 materials in product form of:(1)bar of ASME SB164, annealed, hot- or cold-worked; (2)seamless pipe & tube of ASME SB165, annealed; (3)ASME SB564 UNS N04400 forging, annealed; (4)plate of ASTM B127, annnealed; (5)seamless tube of ASTM B163 with O.D≤3″, annealed; (6)Gr.WPNC seamless & welding fittings of ASME SB-366, annealed.

2). Tensile Strength – Temperature Table for Monel 400 Group B

Temperature	-20~100	200	300	400	500	600	650
Tensile Strength	75.0	75.0	75.0	75.0	75.0	75.0	74.9
Temperature	700	750	800	850	900	950	1000
Tensile Strength	72.3	69.0	65.1	60.8	56.6	53.1	50.8

*The unit of temperature: °F, not exceeding; the unit of tensile strength: ksi.
*Group B refers to Monel 400 materials in product form of: (1) Bar or rod of ASTM B164, hot worked; (2) Plate of ASTM B127, as-rolled; (3) Round bar of ASME SB164 with 12″＜O.D≤14″, hot worked.

3). Tensile Strength – Temperature Table for Monel 400 Group C

Temperature	-20~100	200	300	400	500	600	650	700	750	800
Tensile Strength	80.0	80.0	80.0	80.0	79.9	78.7	77.3	75.3	72.4	68.6

*The unit of temperature: °F, not exceeding; the unit of tensile strength: ksi.
*Group C refers to Monel 400 round bars of ASME SB164 with O.D≤12″, hot-worked.

4). Tensile Strength – Temperature Table for Monel 400 Group D

Temperature	-20~100	200	300	400	500	600	650	700	750	800
Tensile Strength	84.0	84.0	84.0	84.0	83.9	82.6	81.2	79.0	76.0	72.0

*The unit of temperature: °F, not exceeding; the unit of tensile strength: ksi.
*Group D refers to Monel 400 round bars of ASME SB164 with O.D＜1/2″ & 3.5″＜O.D≤4″, cold rolled, stress relieved.

5). Tensile Strength – Temperature Table for Monel 400 Group E

Temperature	-20~100	200	300	400	500	600	650
Tensile Strength	85.0	85.0	85.0	84.9	84.9	83.7	82.2
Temperature	700	750	800	850	900	950	1000
Tensile Strength	79.9	76.8	72.9	68.6	64.2	60.2	57.5

*The unit of temperature: °F, not exceeding; the unit of tensile strength: ksi.
*Group E refers to seamless tube of ASTM B163/ B165 UNS N04400 seamless pipe or tube, stress relieved.

6). Tensile Strength – Temperature Table for Monel 400 Group F

Temperature	-20~100	200	300	400	500	600	650	700	750	800
Tensile Strength, *a	87.0	87.0	87.0	87.0	86.9	85.6	84.1	81.9	78.7	74.6
Tensile Strength, *b	110.0	110.0	110.0	110.0	109.9	108.2	106.3	103.5	99.6	94.3

*The unit of temperature: °F, not exceeding; the unit of tensile strength: ksi.
*a refers to ASME SB164 UNS N04400 round bar with 0.5″≤O.D≤3.5″ cold-rolled & stress-relieved.
*b refers to ASME SB164 UNS N04400 round bar with O.D＜0.5″ cold rolled.

6. Weldability, Workability & Heat Treatment

Monel 400 can be readily joined by welding processes including shielded metal arc welding(SMAW), gas tungsten arc welding (GTAW) and gas metal arc welding(GMAW). Corresponding fillers or electrodes shall be selected. Since Alloy 400 is softer than most steels, it can be hot formed or cold formed into almost any shape following with machining process. Generally, Monel 400 products should be annealed at a temperature of 1470°F (full annealing) and pickling is often required to produce bright and clean surfaces on the alloy.

7. Modulus of Elasticity of Monel 400

Temperature, °F	-325	-200	-100	70	200	300	400	500	600
Modulus of Elasticity, E	27.8	27.2	26.8	26.0	25.5	25.1	24.7	24.3	23.9
Temperature, °F	700	800	900	1000	1100	1200	1300	1400	1500
Modulus of Elasticity, E	23.6	23.1	22.7	22.2	21.7	21.2	20.6	20.0	19.4

*The unit of modulus of elasticity shall be “10⁶ psi”.
*The moduli of elasticity of Monel 400 at different temperatures.

8. Thermal Conductivity & Thermal Diffusivity of Monel 400

1). Thermal Conductivity of Monel 400(UNS N04400)

Temperature, °F	70	100	150	200	250	300	350	400	450	500
Thermal Conductivity	12.6	12.9	13.4	13.9	14.5	15.0	15.6	16.1	16.6	17.0
Temperature, °F	550	600	650	700	750	800	850	900	950	1000
Thermal Conductivity	17.5	17.9	18.4	18.9	19.3	19.9	20.4	20.9	21.5	22.0

*The unit of thermal conductivity is Btu/hr-ft-°F.

2). Thermal Diffusivity of Monel 400(UNS N04400)

Temperature, °F	70	100	150	200	250	300	350	400
Thermal Diffusivity	0.224	0.228	0.234	0.241	0.247	0.254	0.261	0.268
Temperature, °F	450	500	550	600	650	700	750	800
Thermal Diffusivity	0.275	0.280	0.285	0.289	0.291	0.292	0.293	0.293

*The unit of thermal diffusivity is ft²/hr.

9. Thermal Expansion Properties of Monel 400

1). Instantaneous Coefficient of Thermal Expansion of Monel 400

Temperature, °F	70	100	150	200	250	300	350	400	450	500
Coefficent A	7.7	7.9	8.2	8.4	8.6	8.8	8.9	9.1	9.1	9.2
Temperature, °F	550	600	650	700	750	800	850	900	950	1000
Coefficent A	9.3	9.3	9.3	9.4	9.4	9.4	9.5	9.5	9.5	9.6
Temperature, °F	1050	1100	1150	1200	1250	1300	1350	1400	1450	1500
Coefficent A	9.6	9.7	9.7	9.8	9.9	9.9	10.0	10.0	10.0	10.1

*A refers to the instantaneous coefficient of thermal expansion of Monel 400 with an unit of 10^-6in./in./°F.

2). Mean Coefficient of Thermal Expansion of Monel 400

Temperature, °F	-325	-150	-50	70	100	150	200	250	300	350	400
Coefficent B	5.8	6.8	7.2	7.7	7.8	7.9	8.1	8.2	8.3	8.4	8.5
Temperature, °F	450	500	550	600	650	700	750	800	850	900	950
Coefficent B	8.6	8.7	8.7	8.8	8.8	8.9	8.9	8.9	9.0	9.0	9.0
Temperature, °F	1000	1050	1100	1150	1200	1250	1300	1350	1400	1450	1500
Coefficent B	9.1	9.1	9.1	9.1	9.2	9.2	9.2	9.2	9.3	9.3	9.3

*B refers to the mean coefficient of thermal expansion of Monel 400 with an unit of 10^-6in./in./°F.
*The tabulated temperature values shall be interpreted as “going from 70°F to the indicated temperature”.

3). Linear Thermal Expansion of Monel 400

Temperature, °F	-325	-150	-50	70	100	150	200	250	300	350	400
Coefficent C	-2.7	-1.8	-1.0	0	0.3	0.8	1.3	1.8	2.3	2.8	3.4
Temperature, °F	450	500	550	600	650	700	750	800	850	900	950
Coefficent C	3.9	4.5	5.0	5.6	6.1	6.7	7.3	7.8	8.4	9.0	9.5
Temperature, °F	1000	1050	1100	1150	1200	1250	1300	1350	1400	1450	1500
Coefficent C	10.1	10.7	11.3	11.8	12.4	13.0	13.6	14.2	14.8	15.4	16.0

*C refers to the linear thermal expansion of Monel 400 with an unit of in./100 ft.
*The tabulated temperature values shall be interpreted as “going from 70°F to the indicated temperature”.

The tabulated data in above 3 tables are for information and it is not to be implied that Monel 400 materials are suitable for all temperature ranges shown.

10. Allowable Stress – Temperature of Monel 400

1). Monel 400 Group 1: Allowable Stress – Temperature Table

Metal Temperature, °F	-20~100	200	300	400	500	600
Max. Allowable Stress, ksi	16.7	14.6	13.6	13.2	13.1	13.1
Metal Temperature, °F	650	700	750	800	850	900
Max. Allowable Stress, ksi	13.1	13.0	12.9	12.7	11.0	8.0

*Group 1 refers to Monel 400 bar, seamless pipe & tube (＞5″ in OD), and forging of annealed condition.
*Metal temperature shall be interpreted as “not exceeding”.

2). Monel 400 Group 2: Allowable Stress – Temperature Table

Metal Temperature, °F	-20~100	200	300	400	500	600
Max. Allowable Stress, ksi	18.7	16.4	15.2	14.7	14.7	14.7
Metal Temperature, °F	650	700	750	800	850	900
Max. Allowable Stress, ksi	14.7	14.6	14.5	14.3	11.0	8.0

*Group 2 refers to Monel 400 plate, seamless tube(≤3″), seamless pipe & tube(≤5″), seamless & welded fittings of annealed condition.
*Metal temperature shall be interpreted as “not exceeding”.

3). Monel 400 Group 3: Allowable Stress – Temperature Table

Metal Temperature, °F	-20~100	200	300	400	500	600
Max. Allowable Stress, ksi	20.0	19.4	18.6	17.9	17.6	17.3
Metal Temperature, °F	650	700	750	800	850	900
Max. Allowable Stress, ksi	17.2	17.0	16.8	14.5	8.5	4.0

*Group 3 refers to Monel 400 hot-worked bars(ASME SB164) with hexagonal section(54mm ~102mm).
*Metal temperature shall be interpreted as “not exceeding”.

4). Monel 400 Group 4: Allowable Stress – Temperature Table

Metal Temperature, °F	-20~100	200	300	400	500	600
Max. Allowable Stress, ksi	21.4	21.4	21.4	21.4	21.4	21.4
Metal Temperature, °F	650	700	750	800	850	900
Max. Allowable Stress, ksi	21.4	20.7	18.5	14.5	8.5	4.0

*Group 4 refers to Monel 400 as-rolled plate and hot-worked bar or rod with round, square or rectangle section(305mm~356mm).
*Metal temperature shall be interpreted as “not exceeding”.

5). Monel 400 Group 5: Allowable Stress – Temperature Table

Metal Temperature, °F	-20~100	200	300	400	500	600
Max. Allowable Stress, ksi	22.9	22.9	22.9	22.9	22.9	22.9
Metal Temperature, °F	650	700	750	800	850	900
Max. Allowable Stress, ksi	22.8	22.0	18.5	14.5	8.5	4.0

*Group 5 refers to Monel 400 hot worked bars with round, square or rectangle section ≤305mm, or with hexagonal section ≤54mm.
*Metal temperature shall be interpreted as “not exceeding”.

6). Monel 400 Group 6: Allowable Stress – Temperature Table

Metal Temperature, °F	-20~100	200	300	400	500
Max. Allowable Stress, ksi	24.3	24.3	24.3	24.3	24.3
Metal Temperature, °F	600	650	700	750	800
Max. Allowable Stress, ksi	23.9	23.5	22.8	18.0	12.7

*Group 6 refers to Monel 400 seamless tube (ASME SB163), seamless pipe & tube(ASME SB165) funished in stress-relieving condition.
*Metal temperature shall be interpreted as “not exceeding”.

All tabulated values above are based on ASME Boiler & Pressure Vessel Code Section II, Part D.

11. Product Forms and Standards of Monel 400

Product Form	Standard
Plate, Strip, Sheet	ASTM B127, DIN 17750
Bar, Rod, Wire	ASTM B164, AMS 4675
Seamless Pipe & Tube	ASTM B165, B829, B163
Welded Pipe & Tube	ASTM B725, B730, B751, B775
Welded Fittings	ASTM B366
Forged Flanges and Fittings	ASTM B564

Monel 400 Ring

Recently, Yaang has supplied a nickel-copper alloy Monel 400 ring to a Korean client. The ring was forged to ASTM B564 UNS N04400 annealing heat treated and was delivered to an US client in Houston.

Actual Chemical Composition & Mechanical Properties of Monel 400 Ring

Item	C	Mn	Si	S	Cu	Ni	Fe	*Y.S	*T.S	*EL.
Monel 400 Ring	0.11	1.35	0.21	0.002	32.47	63.59	2.08	245	580	45

*For chemical composition, unit: wt %; Y.S, T.S, EL.: yield strength MPa, tensile strength MPa, elongation %.

Monel 400 (UNS N04400) seamless tubes manufactured to ASTM B163 are mainly used for condenser or heat-exchanger service. These tubes are generally furnished in small size with light wall: from 3″ (76.2 mm) and under in outside diameter with minimum wall thickness of 0.148″ (3.76 mm) and under, and with an average wall thickness of 0.165″(4.19 mm) and under.

Manufacture, Condition, Finish, Hydro Test Pressure

The Monel 400 tubes of ASTM B163 can be manufactured by either hot-rolling or cold-rolling process. It shall be furnished in either annealed or stress-relieved condition with relative surface finishes. The hydrostatic test pressure for Monel 400 tubes shall be 17.5 ksi [120.6 MPa].

Chemical Composition & Mechanical Properties

It has the same chemical composition as that of ASTM B165 UNS N04400. Mechanical properties are listed below,

Condition	Tensile Strength, min. ksi [MPa]	Yield Strength, min. ksi [MPa]	Elongation, min. %	Hardness, HRB
Annealed	70 [483]	28 [193]	35	–
Stress-Relieved	85 [586]	55 [379]	15	≤75

*The mechanical properties of ASTM B163 UNS N04400.

Bending of Tube

The tubes are usually bent to suit for condenser or heat-exchanger service. The minimum bending radius shall be determined by tube O.D, average tube wall, and condition of the tube.

The ASTM B165 (identical to ASME SB-165) is the standard specification covering nickel-copper alloy Monel 400 (UNS N04400) in the form of cold-worked seamless pipe and tube. Yaang supplies Monel 400 seamless pipes sized from 2″ to 16″ covering nominal wall thicknesses of SCH10, SCH20, SCH40, SCH80, XS and STD.

Chemical Composition of ASTM B165 UNS N04400

Element	Content, %
Nickel [Ni]	≥63.0
Copper [Cu]	28.0~34.0
Iron [Fe]	≤2.50
Manganese [Mn]	≤2.00
Carbon [C]	≤0.30
Silicon [Si]	≤0.50
Sulfur [S]	≤0.024

*The tabulated values are for heat analysis.

Mechanical Properties of ASTM B165 UNS N04400

Condition & Size	Tensile Strength, min.  ksi [MPa]	Yield Strength, min.  ksi [MPa]	Elongation, min. %
*A	70 [480]	28 [195]	35
*B	70 [480]	25 [170]	35
*C	85 [585]	55 [380]	15

*A:seamless pipe or tube with O.D≤5″, annealed; *B: seamless pipe or tube with O.D>5″, annealed; *C: all sizes, stress relieved.

Condition & Finish

The seamless pipe or tube manufactured to ASTM B165 shall be furnished in annealed or stress-relieved condition. The surface of annealed pipe or tube is soft, with a dull matte finish. The stress relieving refers to thermally treated below the annealing temperature to relieve the major portion of the internal stresses. It will be furnished with a thin, light- to medium- dark surface.

Monel 400 flanges manufactured to ASME B16.5 are usually made from two forms of raw material: ASTM B564 UNS N04400 forgings or ASTM B127 UNS N04400 plates. According to the standard, the pressure-temperature ratings can be furnished in two unit systems: ISO and US customary.

Pressure-Temperature Ratings for Monel 400: ISO Unit

Temp. °C	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
-29~38	15.9	41.4	55.2	82.7	124.1	206.8	344.7
50	15.4	40.2	53.7	80.5	120.7	201.2	335.3
100	13.8	35.9	47.9	71.9	107.8	179.7	299.5
150	12.9	33.7	45.0	67.5	101.2	168.7	281.1
200	12.5	32.7	43.6	65.4	98.1	163.5	272.4
250	12.1	32.6	43.5	65.2	97.8	163.0	271.7
300	10.2	32.6	43.5	65.2	97.8	163.0	271.7
325	9.3	32.6	43.5	65.2	97.8	163.0	271.7
350	8.4	32.6	43.4	65.1	97.7	162.8	271.3
375	7.4	32.4	43.2	64.8	97.2	161.9	269.9
400	6.5	32.1	42.8	64.2	96.2	160.4	267.4
425	5.5	31.6	42.2	63.3	94.9	158.2	263.6
450	4.6	26.9	35.9	53.8	80.7	134.5	224.2
475	3.7	20.8	27.7	41.5	62.3	103.8	173.0

*Working pressures by classes, unit: bar.

Pressure-Temperature Ratings for Monel 400: US Customary Unit

Temp. °F	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
-20~100	230	600	800	1200	1800	3000	5000
200	200	525	700	1050	1575	2630	4380
300	190	490	655	980	1470	2450	4080
400	180	475	630	945	1420	2365	3940
500	170	475	630	945	1420	2365	3940
600	140	475	630	945	1420	2365	3940
650	125	475	630	945	1420	2365	3940
700	110	470	625	940	1410	2350	3920
750	95	465	620	930	1395	2330	3880
800	80	460	610	915	1375	2290	3820
850	65	375	505	755	1130	1885	3145
900	50	275	365	550	825	1370	2285

*Working pressures by classes, unit: psig.

ASME B16.5 Class 150 Flange

1. Technical Drawings for ASME B16.5 Class 150 Flanges

2. Flange & Bolting Dimensions for Class 150

All dimensions are provided in both mm and inch units. The two unit system shall be used respectively and exclusively. The bolting of ASME B16.5 Class 150 flanges can be furnished by stud bolt with nuts or machine bolt with nuts. Stud bolts can be used for RF or RTJ end facing while machine bolts are only used for RF facing. Dimensions of ASME B16.5 Class 150 flanges in below tables shall be furnished with RF facing. For other facings, please contact us for detailed specification.

NPS	O mm inch	To mm inch	T1 mm inch	X mm inch	Ah mm inch	ro mm inch	Do mm inch
10	405 16.00	28.6 1.12	30.2 1.19	305 12.00	273.0 10.75	13 0.50	–
12	485 19.00	30.2 1.19	31.8 1.25	365 14.38	323.8 12.75	13 0.50	–
14	535 21.00	33.4 1.31	35.0 1.38	400 15.75	355.6 14.00	13 0.50	–
16	595 23.50	35.0 1.38	36.6 1.44	457 18.00	406.4 16.00	13 0.50	–
18	635 25.00	38.1 1.50	39.7 1.56	505 19.88	457.0 18.00	13 0.50	–
20	700 27.50	41.3 1.62	42.9 1.69	559 22.00	508.0 20.00	13 0.50	–
24	815 32.00	46.1 1.81	47.7 1.88	663 26.12	610.0 24.00	13 0.50	–

*O:outside diameter of flange

 T_o:minimum flange thickness of W/N, S/O, Blind, THD, S/W; 

 T₁:minimum thickness of lap joint flange;

*X:diameter at hub; 

 A_h:hub diameter at the beginning of chamfer for W/N; 

 r_o: corner bore radius of lapped flange; 

 D_o:depth of socket.

NPS	Y1 mm inch	Y2 mm inch	Y3 mm inch	Ta mm inch	B1 mm inch	B2 mm inch	B3 mm inch
10	100 3.94	48 1.88	49 1.94	49 1.94	254.6 10.02	276.2 10.88	277.4 10.92
12	113 4.44	54 2.12	56 2.19	56 2.19	304.8 12.00	327.0 12.88	328.2 12.92
14	125 4.94	56 2.19	79 2.25	57 2.25	–	359.2 14.14	360.2 14.18
16	125 4.94	62 2.44	87 2.50	64 2.50	–	410.5 16.16	411.2 16.19
18	138 5.44	67 2.62	97 2.69	68 2.69	–	461.8 18.18	462.3 18.20
20	143 5.62	71 2.81	103 2.88	73 2.88	–	513.1 20.20	514.4 20.25
24	151 5.94	81 3.19	111 3.25	83 3.25	–	616.0 24.25	616.0 24.25

*Y₁:length through hub of welding neck flange

 Y₂:length through hub of threaded, S/O and S/W flange;

 Y₃:length through hub of lapped flange.

*T_a:minimum thread length of threaded flange;

 B₁:bore diameter of welding neck flange or lower part of socket welding flange.

*B₂:bore diameter of slip on flange or upper part of socket welding flange;

 B₃:bore diameter of lap joint(lapped) flange.

NPS	W mm inch	R mm inch	d inch	n	do inch	LSRF mm inch	LSRTJ mm inch	LMRF mm inch
1/2	60.3 2.38	34.9 1.38	5/8	4	1/2	55 2.25	–	50 2.00
3/4	69.9 2.75	42.9 1.69	5/8	4	1/2	65 2.50	–	50 2.00
1	79.4 3.12	50.8 2.00	5/8	4	1/2	65 2.50	75 3.00	55 2.25
1-1/4	88.9 3.50	63.5 2.50	5/8	4	1/2	70 2.75	85 3.25	55 2.25
1-1/2	98.4 3.88	73.0 2.88	5/8	4	1/2	70 2.75	85 3.25	65 2.50
2	120.7 4.75	92.1 3.62	3/4	4	5/8	85 3.25	95 3.75	70 2.75
2-1/2	139.7 5.50	104.8 4.12	3/4	4	5/8	90 3.50	100 4.00	75 3.00
3	152.4 6.00	127.0 5.00	3/4	4	5/8	90 3.50	100 4.00	75 3.00
3-1/2	177.8 7.00	139.7 5.50	3/4	8	5/8	90 3.50	100 4.00	75 3.00
4	190.5 7.50	157.2 6.19	3/4	8	5/8	90 3.50	100 4.00	75 3.00
5	215.9 8.50	185.7 7.31	7/8	8	3/4	95 3.75	110 4.25	85 3.25
6	241.3 9.50	215.9 8.50	7/8	8	3/4	100 4.00	115 4.50	85 3.25
8	298.5 11.75	269.9 10.62	7/8	8	3/4	110 4.25	120 4.75	90 3.50

NPS	W mm inch	R mm inch	d inch	n	do inch	LSRF mm inch	LSRTJ mm inch	LMRF mm inch
10	362.0 14.25	323.8 12.75	1	12	7/8	115 4.50	125 5.00	100 4.00
12	431.8 17.00	381.0 15.00	1	12	7/8	120 4.75	135 5.25	100 4.00
14	476.3 18.75	412.8 16.25	1 1/8	12	1	135 5.25	145 5.75	115 4.50
16	539.8 21.25	469.9 18.50	1 1/8	16	1	135 5.25	145 5.75	115 4.50
18	577.9 22.75	533.4 21.00	1 1/4	16	1 1/8	145 5.75	160 6.25	125 5.00
20	635.0 25.00	584.2 23.00	1 1/4	20	1 1/8	160 6.25	170 6.75	140 5.50
24	749.3 29.50	692.2 27.25	1 3/8	20	1 1/4	170 6.75	185 7.25	150 6.00

*W:diameter of bolt circle

 d:diameter of bolt holes;

 n:number of bolts;

 d_o:diameter of bolts;

 R:outside diameter of RF.

*L_SRF:length of stud bolts for raised face; 

 L_SRTJ:length of stud bolts for ring joint; 

 L_MRF:length of machine bolts for raised face.

Analysis on Ductility and Fracture of Monel 400

The high-temperature tension tests for Monel 400 specimens were conducted at 600°C, 700°C, 800°C, 900°C, 1000°C, and 1100°C. The elongation, reduction of area, and fracture surface at elevated temperatures are illustrated respectively.

Elongation & Reduction of Area Chart for Monel 400

When the test temperature increases from 600°C to 700°C, the elongation value decreases from 13.26% to 11.22% while the reduction of area decreases from 24.26% to 20.47%. The ductility of Monel 400 decreases as the temperature goes up in this range. As the test temperature increases from 700°C to 900°C, the elongation value increases from 11.22% to 20.05% while the reduction of area increases from 20.47% to 60.05%. The ductility of Monel 400 increases as the temperature goes up in this range. As the temperature rises up from 900°C to 1100°C, the ductility decreases again. Monel Alloy 400 exhibits hot brittleness between 600°C and 800°C.

The Fracture of Monel 400 Specimens at Elevated Temperatures

From the macrostructure after fracture, obvious necking of Monel 400 is observed at temperatures between 800°C to 1000°C and it achieves maximum at 900°C. It proves that Monel 400 has improved ductility at this temperature range.

The microstructure of the fracture surface of Monel 400 at 600°C, 700°C and 800°C are attained by SEM method. Both pictures A and B exhibit quasi-cleavage fracture in river pattern. It indicates the brittle fracture. Some dimples are observed in Picture C except for cleavage fracture. It proves that the ductility shall be improved at 800°C.

Mechanical Properties of Monel 400 Alloy at Elevated Temperatures

According to the records of tension test on Monel 400 alloy at elevated temperatures, the stress-strain chart, yield strength – temperature chart, and tensile strength- temperature chart were established.

The Stress-Strain Chart for Monel 400 at Elevated Temperatures

The Yield & Tensile Strength – Temperature Chart for Monel 400

Analysis on Test Result

As illustrated above, the yield strength and tensile strength were measured at several elevated temperatures: 600°C, 700°C, 800°C, 900°C, 1000°C, 1100°C. The steep elastic deformation section of the stress-strain curve illustrates that Monel 400 can only have very limited elastic deformation. The rate of plastic deformation increases dramatically as the temperature goes up. Meanwhile, the yield strength and tensile strength of Monel 400 alloy decreases as the temperature is elevated.

Tension Test and Analysis on Monel 400 Alloy at Elevated Temperatures

Monel 400 is a typical Nickel-Copper alloy with high strength and excellent corrosion resistance to seawater, hydrofluoric acid, sulfuric acid, and alkalies. They are widely used for marine engineering, chemical and petrochemical industry, and power plant piping, etc. However, due to its low coefficients of thermal conductivity & linear thermal expansion and high susceptibility to hot cracking, failure may occur during the welding of Monel 400 alloys. The study on Monel 400’s mechanical properties at elevated temperatures is necessary.

Monel 400 Specimens Preparation

The testing specimens shall be hot-rolled Monel 400 rods manufactured to ASTM B164 UNS N04400, under annealed condition. Specification: Φ6 x 120 mm, 6 pieces. Its actual chemical composition is attained by PMI testing(all in weight %): C-0.12, Si-0.10, Mn-1.04, Ni-65.8, Cr-0.085, Fe-1.15, Cu-31.8, Ti-0.045, Co: 0.012, Mo: 0.014.

Testing Apparatus

The testing machine is Gleeble 1500D thermal-machanical simulator. The test was conducted in Yaang’s cooperative lab: Inner Mongolia University of Science & Technology(IMUST).

High-Temperature Tension Test Procedures

The Monel 400 specimens shall be tested at temperatures 600°C, 700°C, 800°C, 900°C, 1000°C, and 1100°C, respectively. The heating rate shall be 10°C/s while the cooling rate shall be at 3°C/s. The strain rate imposed on each specimen shall be 10^-3/s. The tensile process shall be conducted in vacuum environment until the specimen is broken. Record the values of stress, strain, tensile strength, yield strength, elongation and area of reduction at each testing temperature. Take scanning electron microscope (SEM) inspection on the fracture surface of the specimen. The test results and further analysis are listed below:

• Mechanical Properties of Monel 400 alloy at elevated temperatures.
• Analysis on ductility and fracture of Monel 400 specimens.

ERNiCu-7 Filler Metal for Welding of Monel 400

ERNiCu-7 is a commonly used filler metal in the welding of Monel 400 piping materials. It is designated as UNS N04060, also known as Monel 60 with nominal composition of 65Ni-30Cu-3Mn-2Ti. The ERNiCu-7 bare welding electrode/ rod can be used in the GTAW (TIG), GMAW, SAW and PAW processes for the welding of Monel 400 (UNS N04400) materials of ASTM B127(plate), ASTM B163(seamless tube), ASTM B165(seamless pipe), and ASTM B164(rod, bar & wire). Titanium contents are added to control porosity with these welding processes. The weld metal has properties similar to those of Monel 400. It has good strength and resists corrosion in many media, including seawater, salt, and reducing acids.

1. Chemical Composition Requirements of ERNiCu-7

Element	Weight, %
C	≤0.15
Mn	≤4.0
Fe	≤2.5
P	≤0.020
S	≤0.015
Si	≤1.25
Cu	Remaining
Ni	62.0~69.0
Al	≤1.25
Ti	1.5~3.0
Others	≤0.50

*The tabulated values are furnished in accordance with AWS A5.14.

2. Mechanical Properties

The mechanical properties of the weld metal may be influenced by a variety of factors in the welding process. These variables include current, voltage, welding speed, gas mixture, dexterity of the welder, and base metal chemical composition, etc. Typically, the minimum weld metal tensile strength for ERNiCu-7 is 70 ksi [380 MPa]. It minimum elongation value is 30%.

3. International Equivalent of ERNiCu-7(Monel 60)

AWS A5.14	Military Designation	AWS A5.11	ISO 18274	DIN 1736 (2.4377)	BS 2901	SFA-5.14
ERNiCu-7	EN60 & RN60	ENiCu-7	SNi 4060	SG-NiCu30MnTi	NA33	UNS N04060

*The P-Number of base metal Monel 400(UNS N04400) is 42.

4. Product Forms and Specification

The ERNiCu-7 filler metals are available in spools and cut-straight lengths in a variety of sizes selected from the following diameters:

O.D(mm)	0.80	0.90	1.14	1.20	1.60	2.40	3.20
O.D(inch)	0.031	0.035	0.045	0.048	0.062	0.094	0.125

*The length of cut-straight length shall be 900 mm ± 2%.
*Diameter tolerance for cut straight lengths(mm):+0.01, -0.07; Diameter tolerance for spools(mm):+0.01, -0.04.

Source: China Monel 400 Flanges Manufacturer – Yaang Pipe Industry (www.steeljrv.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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Nickel Alloy: Hastelloy C-276 (UNS N10276)