Elastic alloys
| Industry Name | NiCr40Al4, 40ХНЮ-ВИ (ЭИ793) |
Product Forms | Rods, Bars, Wires |
General Characteristics
Alloy 3J40 is a precipitation-hardened Ni-Cr-Al high elastic precision alloy, equivalent to Russian grade 40XHЮ. It was developed to solve the weaknesses of conventional elastic alloys, which lacked sufficient hardness, wear resistance and non-magnetic property for precision instrument pivot tips working under impact and corrosive environments.
It is designed for service conditions requiring non-magnetism, high wear resistance, shock resistance and strong corrosion resistance. Its key strengths include ultra-high hardness, high elastic limit, low elastic hysteresis, non-magnetic performance and excellent corrosion resistance. It maintains stable elastic performance under repeated impact and friction loads.
It is commonly compared with constant modulus alloy 3J53. Unlike 3J53 which focuses on stable elastic modulus against temperature change, 3J40 prioritizes high hardness, wear resistance and non-magnetism. It is also contrasted with cobalt elastic alloy 3J21. 3J21 has excellent fatigue strength but contains cobalt, while 3J40 delivers great wear performance without cobalt and works well in corrosive environments.
Element | Content |
Nickel (Ni) | Balance (54.4 – 56.7) |
Chromium (Cr) | 39.0 – 41.0 |
Aluminum (Al) | 3.3 – 3.5 |
Cerium (Ce) | 0.10 – 0.20 |
Iron (Fe) | ≤ 0.50 |
Carbon (C) | ≤ 0.03 |
Silicon (Si) | ≤ 0.20 |
Manganese (Mn) | ≤ 0.10 |
Phosphorus (P) | ≤ 0.010 |
Sulfur (S) | ≤ 0.010 |
Electronics||Non-magnetic contact springs|Elastic reed assemblies|Wear-resistant clamping elements for electronic sensors
Aerospace||Non-magnetic instrument elastic parts|Shock-resistant pivot components for airborne meters|Corrosion-resistant elastic fasteners
Oil & Petrochemical||Non-magnetic wear-resistant spring elements|Instrument pivots used in corrosive medium|Sensor elastic components for downhole tools
Technical Standards | Product Form |
YB/T 5243 | Bar, Wire, Strip, Sheet |
Product form | Size range (mm) |
Forged bar | Dia.70-500 |
Rolled bar | Dia.2.0-70 |
Flat bar | T4-50*W60-300 |
Wire | Dia.0.25-18.0 |
Q1: What is its typical service environment?
A: It is designed for working conditions requiring non-magnetic property, wear resistance, repeated impact and mild corrosive media.
Q2: How does Alloy 3J40 compare with 3J53?
A: 3J40 focuses on non-magnetism and wear resistance. 3J53 is a constant-modulus alloy mainly used for frequency-stable resonant elements, without outstanding wear performance.
Q3: How does Alloy 3J40 compare with 3J21?
A: Both have good elasticity. 3J21 has superior fatigue strength but contains cobalt. 3J40 is cobalt-free, non-magnetic and offers better wear and corrosion resistance.
Q4: What heat treatment rule should we follow?
A: Forming, stamping or bending must be completed before aging treatment. Aging first and then shaping will cause cracking.
Q5: Is Alloy 3J40 truly non-magnetic?
A: Yes. It maintains non-magnetic characteristics after heat treatment, suitable for magnetic-sensitive instrument systems.