En354 alloy steel

Introduction

We manufacture forging ingots, billets, and blooms in alloy steel specifically for En354, tailored for very heavy-duty case hardening applications.

En354 is a low carbon nickel–chromium–molybdenum alloy steel developed for components requiring an extremely hard, wear-resistant surface combined with an exceptionally tough and strong core. It is designed for severe service conditions involving heavy loads, shock, and continuous cyclic stress.

The high nickel content provides outstanding core toughness and fatigue resistance, chromium improves hardenability and wear resistance, while molybdenum enhances deep hardening, strength, and resistance to temper brittleness. En354 offers good machinability in the annealed condition and maintains dimensional stability after heat treatment, making it suitable for forging and precision machining processes.

This steel provides maximum durability, reliability, and long service life for critical industrial applications.

Chemical composition

Element	Content (%)	Function / effect
Carbon (c)	0.10 – 0.20	Ensures tough and ductile core
Manganese (mn)	0.40 – 0.70	Improves hardenability and strength
Silicon (si)	Max 0.35	Increases strength
Nickel (ni)	3.25 – 3.75	Improves toughness and fatigue resistance
Chromium (cr)	1.20 – 1.60	Improves hardenability and wear resistance
Molybdenum (mo)	0.20 – 0.35	Improves deep hardening and strength
Phosphorus (p)	Max 0.035	Impurity; controlled for toughness
Sulphur (s)	Max 0.035	Impurity; controlled for machinability

Mechanical properties (typical, depending on condition & heat treatment)

• Core tensile strength: 850 – 1050 MPa
• Core yield strength: 600 – 800 MPa
• Surface hardness (carburized): 58 – 62 HRC
• Core hardness: 220 – 260 HB
• Impact toughness: Very high
• Fatigue resistance: Excellent

Heat treatment

• annealing: improves machinability before carburizing.
• carburizing: introduces carbon at high temperature to obtain a very hard, wear-resistant surface.
• quenching: rapid cooling to achieve a hard martensitic case with deep hardening.
• tempering: relieves internal stresses while maintaining surface hardness and core toughness.

The heat treatment cycle can be optimized for required case depth and heavy-duty service conditions.

Key features and benefits

• excellent case hardening response with deep hardening
• extremely high core strength and toughness
• superior wear and fatigue resistance
• good machinability in annealed condition
• dimensional stability after heat treatment
• suitable for forging and precision machining

Typical applications

• very heavy-duty gears and pinions
• planetary gear systems
• transmission and differential components
• mining, cement, and power plant machinery parts
• critical automotive and engineering components

Equivalent steel grades

• En354 has several international equivalents, including:
• en36d – close equivalent
• din 1.6582 (approximate)
• 18CrNimo7-6 – application-based comparison

Why choose En354 for your application?

En354 offers the highest level of surface hardness, core toughness, and fatigue resistance among the en35x series. The addition of molybdenum makes it ideal for very heavily loaded components requiring deep hardening and long-term reliability under extreme service conditions.

Comparison table for similar grades

Grade	Carbon (%)	Key applications	Heat treatment	Comments
En354	0.10 – 0.20	Heavy gears, planetary systems	Carburizing + q&t	Ni-cr-mo, highest strength
En353	0.10 – 0.20	Heavy-duty gears	Carburizing + q&t	High ni-cr
En352	0.10 – 0.20	Automotive gears	Carburizing + q&t	High ni
En36	0.12 – 0.18	Heavy gears	Carburizing	Widely used ni-cr steel

Summary

En354 is a nickel–chromium–molybdenum low carbon alloy steel optimized for severe-duty case hardening applications. It delivers a very hard, wear-resistant surface, an exceptionally strong and tough core, and outstanding durability for critical engineering and automotive components.