The different grades and basic characteristics of CA6NM in different countries are briefly introduced
ASTM A487 CA6NM Cylinder of hydraulic accumulator
It is a kind of low carbon martensitic stainless steel. It has good mechanical properties of large section, static fracture toughness and underwater fatigue, and has good cavitation resistance and welding performance. It is an excellent material for Balling line roller screen and Cylinder of hydraulic accumulator.
ASTM A743 CA6NM rollers
1. Material introduction
1.1 Grades: Z6CND16.04.01 (French NFA35 standard)
1.2 Similar grades: 1.4313 (Germany), CA6NM (America), SCS5 (Japan), Z6CND13.04M (France) ZG06Cr13Ni4Mo (China)
1. Material introduction
1.1 Grades: Z6CND16.04.01 (French NFA35 standard)
1.2 Similar grades: 1.4313 (Germany), CA6NM (America), SCS5 (Japan), Z6CND13.04M (France) ZG06Cr16Ni5Mo (China)
1.3 Chinese grade：ZG06Cr13Ni4Mo
1.3.1 forging material
a) Standard: QJ/SK05-06-2004 (enterprise standard)
b) The grade: 0CR13NI4MO
1.3.2 casting material
a) Standard: ASTM A743、ASTM A487
b) Grade: CA6NM
1.4 Chemical composition
| Grades | C | Si | Mn | S | P | Cr | Ni | Mo |
| Z6CND16.04.01 | ≤ 0.07 | ≤ 1.00 | ≤ 1.00 | ≤ 0.030 | ≤ 0.040 | 15.00- 17.00 | 3.50- 5.50 | 0.40- 1.25 |
| 0Cr13Ni4Mo | 0.03- 0.05 | 0.30- 0.60 | 0.50- 1.00 | ≤ 0.020 | ≤ 0.030 | 12.00- 14.00 | 3.50- 4.50 | 0.30- 0.70 |
| CA6NM | ≤ 0.06 | ≤ 1.00 | ≤ 1.00 | ≤ 0.030 | ≤ 0.035 | 11.50- 13.5 | 3.50- 4.50 | 0.40- 1.00 |
1.5 Heat treatment system
The steel is mainly done tempering and tempering treatment, according to different performance requirements have different heat treatment process.
Typical heat treatment processes are as follows:
Annealing treatment 590-640℃ furnace cold
Tempering and tempering treatment 1000-1050℃ normalizing
600-620 ℃ tempering
1.6 Supply status: Generally, casting can be supplied, and profiles (bars, forgings and plates) can also be customized.
1.7 Melting process: smelting can be carried out by means of arc furnace, medium frequency induction furnace, VOD furnace or AOD furnace secondary refining.
1.8 Application: The steel is generally used to make parts with serious cavitation and high requirements on comprehensive mechanical properties, such as runner blade, upper crown, lower ring, leak-stop ring and wear-resisting plate in hydraulic turbine.
In the pump products, mainly used to make the pump impeller with higher requirements of cavitation resistance, or the pump shaft with higher requirements of mechanical properties, but also can be used to make various important parts that bear impact and high load, such as connectors, fasteners, etc.
2. Chemical and physical properties
2.1 Thermal properties
2.1.1 Melting range: 1400-1500℃
2.1.2 Thermal conductivity λ= 0.06-0.065 W/m℃
2.1.3 Specific heat capacity C=460J/kg·℃
2.1.4 Linear expansion coefficient
| θ（℃） | 100 | 600 | 1000 |
| а（10-6/℃） | 10.0 | 10.5 | 12.0 |
2.2 Density： ρ= 7.74-7.75kg/m3
2.3 Resistivity:
| θ（℃） | 20 | 100 |
| Ω·mm2/m | 0.55 | 0.65-0.70 |
2.4 Magnetic property: the steel is martensitic steel with strong ferromagnetism.
2.4.1 Oxidation resistance: the steel has excellent oxidation resistance.
2.4.2 Corrosion resistance: at room temperature, it has good corrosion resistance to general corrosive media (such as salt water nitric acid and some organic acids with low concentration).
3. Mechanical properties
3.1 Tensile properties at room temperature
| Grades | Heat treatment | Tensile properties | Impact toughness | ||||
| σb Mpa | σ0.2 Mpa | δ5 % | Ψ % | HB | Akv J | ||
| Z6CND16.04 | Quenching + tempering | ≥1000 | ≥800 | ≥12 | ≥40 | ≥58 | |
| 0Cr13Ni4Mo | Quenching + tempering | 780-980 | ≥685 | ≥15 | ≥30 | 275-325 | ≥49 |
| ZG06Cr13Ni4Mo | Quenching + tempering | ≥785 | ≥588 | ≥15 | ≥35 | 221-286 | ≥40 |
3.2 Fatigue properties
3.2.1 Underwater fatigue performance σ-1=260-300 MPa
3.3 Elastic properties
3.3.1 Room temperature elastic modulus E= 200GPa
3.4 Fracture property K1C=390MN/m3/2
4. Organization
The metallographic structure of the steel is mainly lamellar martensite.
5. Process performance
5.1 Hot working performance: the forging rolling temperature range is 1050-1150℃, and the final forging temperature is greater than 850℃.
5.2 Welding performance: the steel has good weldability, little quenching tendency in heat-affected zone and small stress.
But welding is strictly prohibited in the as-cast state.
Mending welding and cutting gate riser and other thermal process operations.
The casting shall be treated by 600-650 softening annealing and then repaired or welded before tempering and tempering.
The steel can be welded by various methods, such as manual welding, automatic arc welding, argon arc welding, etc.
5.3 Cutting and Grinding: The steel has high strength and toughness after heat treatment, so the machining performance and grinding performance are good.
