1.6959, 35NiCrMoV12-5, 38ChN3MFA - Special steel for power industry and aviation according to WW and GOST 5632-72
Table of content:
| Standard | Grade | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical composition % | |||||||||||||||
| C: | Si: | Mn: | P: | S: | Cr: | Mo: | Ni: | V: | Al: | ||||||
| DIN | 1.6959 - 35NiCrMoV12-5 | ||||||||||||||
| 0.3-0.4 | 0.15-0.35 | 0.4-0.7 | <0.015 | <0.015 | 1.0-1.4 | 0.35-0.60 | 2.5-3.5 | 0.08-0.20 | <0.015 | ||||||
| GOST | 38ChN2MFA | ||||||||||||||
| 0.35-0.40 | 0.17-0.37 | 0.5-0.7 | <0.008 | <0.008 | 1.4-1.7 | 0.3-0.4 | 2.3-2.6 | 0.15-0.25 | 0.020-0.045 | ||||||
| GOST | 38ChN3MFA | ||||||||||||||
| 0.33-0.40 | 0.17-0.37 | 0.25-0.50 | <0.03 | <0.025 | 1.2-1.5 | 0.35-0.45 | 3.0-3.5 | 0.10-0.18 | - | ||||||
| GOST | 38ChN3MFA-Sh | ||||||||||||||
| 0.33-0.40 | 0.17-0.37 | 0.25-0.50 | <0.025 | <0.015 | 1.2-1.5 | 0.35-0.45 | 3.0-3.5 | 0.10-0.18 | - | ||||||
1.6959, 35NiCrMoV12-5, 38ChN3MFA – description
Special purpose steel applied mainly in aircrafts and energy industry (including nuclear plants), especially for heavy-duty fastenings and studs. The steel may operate under load in the temperature range from -40 to 420 °C.
The steel belongs to weldability group NAKS M03. Hardly weldable steel. Pre-heating is a must, and welding should be followed by stress-relieving. Apply furnance cooling down to 300°C with 20°C per hour max speed, then cool in the air.
Physical and mechanical properties
Physical properties of the steel:
- Density: 7.88 g/cm3
The mechanical properties
- Hard-drawn bars:
- Yield strength Re: > 1080 MPa
- Tensile strength Rm: > 1180 MPa
- Elongation A: > 12 %
- Impact Value KCU. 20°C: > 78 J/sm2
- Percent reduction of area Z: > 50 %
- Hardness HB: < 269 %
- Diameter cone impression: 3.7 %
- Seamless hot-deformed steel pipes for aviation:
- Yield strength Re: > 980 MPa
- Tensile strength Rm: > 1078 MPa
- Elongation A: > 11 %
- Longitudial test pieces:
- KP 640 strength group:
- Thickness: < 100 mm
- Yield strength Re: > 640 MPa
- Tensile strength Rm: > 785 MPa
- Elongation A: > 13 %
- Impact Value KCU. 20°C: > 59 J/sm2
- Percent reduction of area Z: > 42 %
- Hardness HB: 248-293 %
- Diameter cone impression: 3.55-3.85 %
- Thickness: 100-300 mm
- Yield strength Re: > 640 MPa
- Tensile strength Rm: > 785 MPa
- Elongation A: > 12 %
- Impact Value KCU. 20°C: > 49 J/sm2
- Percent reduction of area Z: > 38 %
- Hardness HB: 248-293 %
- Diameter cone impression: 3.55-3.85 %
- Thickness: 300-500 mm
- Yield strength Re: > 640 MPa
- Tensile strength Rm: > 785 MPa
- Elongation A: > 11 %
- Impact Value KCU. 20°C: > 44 J/sm2
- Percent reduction of area Z: > 33 %
- Hardness HB: 248-293 %
- Diameter cone impression: 3.55-3.85 %
- Thickness: 500-800 mm
- Yield strength Re: > 640 MPa
- Tensile strength Rm: > 785 MPa
- Elongation A: > 10 %
- Impact Value KCU. 20°C: > 39 J/sm2
- Percent reduction of area Z: > 30 %
- Hardness HB: 248-293 %
- Diameter cone impression: 3.55-3.85 %
- Thickness: < 100 mm
- KP 685 strength group:
- Thickness: < 100 mm
- Yield strength Re: > 685 MPa
- Tensile strength Rm: > 835 MPa
- Elongation A: > 13 %
- Impact Value KCU. 20°C: > 59 J/sm2
- Percent reduction of area Z: > 42 %
- Hardness HB: 262-311 %
- Diameter cone impression: 3.45-3.75 %
- Thickness: 100-300 mm
- Yield strength Re: > 685 MPa
- Tensile strength Rm: > 835 MPa
- Elongation A: > 12 %
- Impact Value KCU. 20°C: > 49 J/sm2
- Percent reduction of area Z: > 38 %
- Hardness HB: 262-311 %
- Diameter cone impression: 3.45-3.75 %
- Thickness: 300-500 mm
- Yield strength Re: > 685 MPa
- Tensile strength Rm: > 835 MPa
- Elongation A: > 11 %
- Impact Value KCU. 20°C: > 39 J/sm2
- Percent reduction of area Z: > 33 %
- Hardness HB: 262-311 %
- Diameter cone impression: 3.45-3.75 %
- Thickness: 500-800 mm
- Yield strength Re: > 685 MPa
- Tensile strength Rm: > 835 MPa
- Elongation A: > 10 %
- Impact Value KCU. 20°C: > 39 J/sm2
- Percent reduction of area Z: > 30 %
- Hardness HB: 262-311 %
- Diameter cone impression: 3.45-3.75 %
- Thickness: < 100 mm
- KP 735 strength group:
- Thickness: < 100 mm
- Yield strength Re: > 735 MPa
- Tensile strength Rm: > 880 MPa
- Elongation A: > 13 %
- Impact Value KCU. 20°C: > 59 J/sm2
- Percent reduction of area Z: > 40 %
- Hardness HB: 277-321 %
- Diameter cone impression: 3.40-3.65 %
- Thickness: 100-300 mm
- Yield strength Re: > 735 MPa
- Tensile strength Rm: > 880 MPa
- Elongation A: > 12 %
- Impact Value KCU. 20°C: > 49 J/sm2
- Percent reduction of area Z: > 35 %
- Hardness HB: 277-321 %
- Diameter cone impression: 3.40-3.65 %
- Thickness: 300-500 mm
- Yield strength Re: > 735 MPa
- Tensile strength Rm: > 880 MPa
- Elongation A: > 11 %
- Impact Value KCU. 20°C: > 39 J/sm2
- Percent reduction of area Z: > 30 %
- Hardness HB: 277-321 %
- Diameter cone impression: 3.40-3.65 %
- Thickness: < 100 mm
- KP 785 strength group:
- Thickness: < 100 mm
- Yield strength Re: > 785 MPa
- Tensile strength Rm: > 930 MPa
- Elongation A: > 12 %
- Impact Value KCU. 20°C: > 59 J/sm2
- Percent reduction of area Z: > 40 %
- Hardness HB: 293-331 %
- Diameter cone impression: 3.40-3.65 %
- Thickness: 100-300 mm
- Yield strength Re: > 785 MPa
- Tensile strength Rm: > 930 MPa
- Elongation A: > 11 %
- Impact Value KCU. 20°C: > 49 J/sm2
- Percent reduction of area Z: > 35 %
- Hardness HB: 293-331 %
- Diameter cone impression: 3.40-3.65 %
- Thickness: 300-500 mm
- Yield strength Re: > 785 MPa
- Tensile strength Rm: > 930 MPa
- Elongation A: > 10 %
- Impact Value KCU. 20°C: > 39 J/sm2
- Percent reduction of area Z: > 30 %
- Hardness HB: 293-331 %
- Diameter cone impression: 3.40-3.65 %
- Thickness: < 100 mm
- KP 640 strength group:
Heat treatment and working
Recommended working and heat treatment parameters for the alloy:
- Forging: 1100-850 °C
- Rolling: 1150-900 °C
- Quenching: 860 °C
- Tempering: 610-630 °C
- Soft Annealing: 800 °C
We deliver this steel alloy as:
- hot-rolled bars
- Tubes
- Forgings
Replacements, equivalents and other designations:
1.6959, 35NiCrMoV12-5, 38Ch2N2MFA-ATU, 38ChN3MFA, 38ChN3MFA-Sh