Welding Stainless Steel to Nickel-Based Alloys: Technical Solutions and Best Practices

At Ronsco, a leading supplier of stainless steel plate and alloy materials, we understand the increasing demand for reliable welding solutions between stainless steel and nickel-based alloys—especially in fields like petrochemical, aerospace, and nuclear energy. This article explores the core properties of both materials, welding challenges, advanced joining techniques, and essential quality control practices to help engineers achieve stable and high-quality joints.

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1. Material Properties: Stainless Steel vs. Nickel-Based Alloys

Stainless Steel (304/316 Series)

• Primary Composition: Iron-Chromium-Nickel (Fe-Cr-Ni) alloy system

• Key Features:

  • Corrosion Resistance: Passive film forms with Cr content ≥16%

  • Mechanical Strength: Tensile strength ≥515 MPa; elongation ≥40%

• Common Applications:

  • Food-grade machinery

  • Medical equipment

  • Chemical processing systems

Nickel-Based Alloys

• Composition: Nickel ≥50%, with Mo, Cr, Nb as strengthening elements

• Key Advantages:

  • High-Temperature Performance: Maintains ≥70% of room-temp strength at 800°C

  • Corrosion Resistance: Excellent resistance to harsh acids like H₂SO₄ and HF

• Typical Applications:

  • Jet engine parts

  • Petrochemical reactors

  • Nuclear-grade pressure vessels

2. Welding Challenges Between Stainless Steel and Nickel Alloys

Metallurgical Incompatibility

• Thermal Expansion Mismatch: Nickel alloys have 15–20% lower thermal expansion than stainless steel

• Phase Transformation Range: Difference of 200–300°C

• Oxidation Behavior: Cr₂O₃ (dense) vs. NiO (porous) affects joint surface stability

Process Control Issues

• Hot Cracking Sensitivity: Ni-Al/Mg systems may form liquation cracks

• Element Segregation: Fe-Ni-Cr alloys tend to exhibit dendritic segregation

3. Advanced Welding Techniques

Transition Layer Welding

• Filler Metal Recommendation: ERNiCrMo-3 (per AWS A5.14)

• Key Process Parameters:

  • Current Type: DCEN (Direct Current Electrode Negative)

  • Heat Input: 8–12 kJ/cm

  • Interpass Temperature: ≤150°C

This technique helps bridge thermal and metallurgical differences between the two metals.

High-Energy Beam Welding Comparison

4. Quality Control Requirements

Pre-Weld Preparation

• Groove Finish: Machining + electropolishing (Ra ≤1.6 μm)

• Cleaning Procedure:

  • Ultrasonic cleaning in acetone (15 minutes)

  • Alcohol degreasing for surface purity

In-Process Control

• Shielding Gas: Argon + 2% H₂ (dew point ≤–60°C)

• Welding Sequence:

  1. Weld the nickel alloy transition layer

  2. Then weld the stainless steel side

Post-Weld Heat Treatment

• Solution Annealing: 1100°C × 1 hour followed by water quenching

• Stress Relief Annealing: 650°C × 2 hours, air-cooled

Inspection Standards

• Radiographic Testing: Compliant with ASME Section V, Class B

• Corrosion Testing: Passes ASTM G28 Method A

Why Partner with Ronsco?

At Ronsco, we not only supply high-quality stainless steel plates and nickel-based alloys, but we also provide tailored welding recommendations, technical documentation, and machining services. Our materials are widely used in marine engineering, pressure vessels, energy systems, and aerospace-grade fabrication.

To explore product specifications or get welding support, visit:
👉 www.ronscoplate.com

Contact Us

Need help selecting filler metals, defining process parameters, or requesting data sheets?
📧 Email us at: info@ronscoplate.com
📞 Or leave a message directly via our Contact Page

✅ Stay tuned to Ronsco News for more technical guides and material innovations in the stainless and nickel alloy industry.