Descriptions of 4140 Induction Harden Chrome Plated Bar

1. Extreme wear resistance

Hard chrome plating reduces the friction coefficient to 0.1-0.2, which is 90% lower than the wear rate of untreated steel

Can withstand >50MPa contact pressure, suitable for high-frequency reciprocating parts

2. Corrosion resistance enhancement

Porosity of the plating ≤3 micropores/cm² (better than AMS 2460 standard)

Compatible with humid, industrial chemicals and weak acid environments (PH≥4)

3. Precision dimensional control

Plating thickness tolerance ±0.005mm (supports third-party SGS testing)

Straightness ≤0.3mm/m, meeting ISO 2768-m level accuracy

Chemical Composition + Mechanical Properties

Applicatinos of 4140 Incuction Hardened Chrome Bar

4140 alloy steel has high fatigue strength and low notch sensitivity, high low temperature impact toughness, no obvious temper brittleness, and is mainly used in the quenched and tempered state.

4140 Induction Hardened Chrome bar is used to manufacture high-strength parts and parts with large cross-sections and other stress-bearing components under impact load.

Such as high strength Hydraulic cylinder rods, penaumatic cylinder rods, the transmission eccentric shaft of the horizontal forging machine, the crankshaft of the forging press.

1. Industrial machinery
Hydraulic and pneumatic systems: such as hydraulic cylinder piston rods and pneumatic valve stems, which need to withstand high pressure and frequent reciprocating motion.
Transmission system: gear shafts, camshafts, couplings, which require high torsional strength.
Molds and injection molding machines: ejectors and guide pillars, which require high precision and wear resistance.

2. Automobiles and transportation
Drive shafts: withstand engine torque and road impact.
Suspension parts: steering knuckles, suspension links, which need to resist fatigue and impact.
Gearbox gear shafts: wear resistance and deformation resistance at high speeds.

3. Aerospace
Landing gear parts and actuator shafts need to be lightweight and high-strength.

4. Energy and heavy industry
Wind turbine main shafts and mining machinery shafts, which can cope with extreme loads and harsh environments.

4140 Induction Hardened Chrome Bar Quality Control System

Coating Inspection:

• XRF Spectrometer (X-ray fluorescence):
  Used to analyze the composition of the chrome plating. It tells you exactly what elements are present—important for verifying chrome purity and RoHS compliance.

• Eddy Current Thickness Gauge:
  Measures coating thickness without damaging the surface. Essential for checking if the chrome layer is uniform and within spec across the bar.

Performance Test:

• Rockwell Hardness Tester (HRC scale):
  Confirms the surface hardness after induction hardening. For a 4140 bar, typical HRC is around 50–60. Critical for ensuring wear resistance.

• Rotary Wear Tester (ASTM G99):
  This test simulates friction and wear under controlled conditions. It evaluates how well the chrome layer holds up over time under mechanical contact.

Certification Standard:

• RoHS (Restriction of Hazardous Substances):
  Confirms the product is environmentally compliant—free from restricted toxic materials like lead, cadmium, hexavalent chromium (Cr6+), etc.

FAQs

1. Can 4140 be induction hardened?

Yes, 4140 steel can be induction hardened. It contains enough carbon and alloy elements to allow the surface to harden while the core stays tough. This process improves wear resistance and is often used in shafts, gears, and other parts that need strength on the outside.

2. Can you chrome plate 4140?

Yes, you can chrome plate 4140 steel. Before plating, the surface needs to be cleaned and treated to ensure good adhesion. Chrome plating adds corrosion resistance and a smooth finish, making it useful for hydraulic rods, rollers, and other high-wear parts.

3. What is an induction hardened chrome bar?

An induction hardened chrome bar is a steel rod with a hard outer layer and a chrome-plated surface. The hardening process gives it strong wear resistance, while the chrome adds a smooth, corrosion-resistant finish. These bars are used in machinery, hydraulic systems, and other demanding environments.

Ordering & Customization Information

Q: Can this material be used in high temperature environments?

A: The recommended long-term use temperature of the substrate SAE 4140 is ≤300°C; the hard chrome coating may oxidize and peel off at ＞400°C, and an alternative solution (such as thermal spray ceramic) needs to be selected

Q: Can you provide pre-processing services (such as turning/grinding)?

A: Support customized processing according to drawings, with an accuracy of IT7 level (roughness Ra≤0.8μm after grinding)

Q: Can you provide samples?

A: φ20×100mm standard test rods can be provided free of charge (limited to corporate users)

Q: How long is the construction period?

A: Regular sizes are shipped within 72 hours, customized sizes, according to customer quantity, delivery within 30 days at the earliest, support DDP international trade terms