Material Cluster — Nickel-Chromium

Inconel

High-temperature and sour-service nickel-chromium alloys — see the grade table below for full datasheets and equivalents within this family.

See All Grades ↓
DRAWINGNPRO-MAT-INC-001
FAMILYNICKEL-CHROMIUM
GRADES3 GRADES
STATUSREFERENCE / EDUCATIONAL
Family Overview

High-temperature and sour-service nickel-chromium alloys

Inconel is a family of nickel-chromium alloys built for high-temperature strength retention and resistance to oxidizing and sour environments beyond what stainless and duplex steels can provide. It spans a wide range within the family — from the general-purpose 600, through the molybdenum-bearing 625 for the highest temperature and sour service, to the precipitation-hardened 718 for applications needing exceptional strength.

Choosing within the family starts with the actual driver: general high-temperature/caustic resistance (600), high-temperature plus sour or chloride resistance (625), or a genuine structural strength requirement (718).

Fig. — Grades in This Family

Grades in this family

GradeDesignationBest For
Inconel 600UNS N06600General high-temperature and caustic service
Inconel 625UNS N06625~980°C oxidation resistance, sour (H₂S) service
Inconel 718UNS N07718Precipitation-hardened, exceptional strength-to-weight
Trade-offs

Advantages & limitations of the family

Advantages

  • Excellent high-temperature strength and oxidation resistance
  • 625 offers strong resistance to sour and chloride service
  • 718 provides exceptional strength where genuinely needed

Limitations

  • Significant cost premium over stainless and duplex
  • Slower machining, higher tool wear than stainless
  • 718 requires post-machining age-hardening heat treatment
FAQ — Schema Marked

Questions about the Inconel family

600 for general high-temperature/caustic service, 625 if sour gas or chloride resistance at high temperature is required, and 718 only if there's a genuine structural strength driver beyond standard pressure design.

No — 718's primary advantage is strength via precipitation hardening, not superior corrosion resistance. For corrosion-driven applications, 625 is usually the more appropriate and cost-effective choice.

It varies by grade — 625 handles oxidation resistance to roughly 980°C, though the practical pressure-part design temperature is governed by allowable stress at temperature, not oxidation limits alone.

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