16CrNi4 alloy steel

Introduction

We manufacture forging ingots, billets, and blooms in alloy steel specifically for 16CrNi4, tailored for case hardening applications.

16CrNi4 is a low carbon nickel–chromium alloy steel designed for components that require a hard, wear-resistant surface combined with a tough and ductile core. It is widely used in automotive and general engineering applications subjected to moderate loads and repeated stress.

The controlled nickel content provides good core toughness and fatigue resistance, while chromium improves hardenability and wear resistance after carburizing. 16CrNi4 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 offers a cost-effective solution for case-hardened components with reliable performance.

Chemical composition

Element	Content (%)	Function / effect
Carbon (c)	0.14 – 0.19	Enables case hardening and tough core
Manganese (mn)	0.40 – 0.70	Improves hardenability and strength
Silicon (si)	Max 0.40	Increases strength
Nickel (ni)	0.80 – 1.10	Improves toughness and fatigue resistance
Chromium (cr)	0.90 – 1.20	Improves hardenability and wear resistance
Phosphorus (p)	Max 0.025	Impurity; controlled for toughness
Sulphur (s)	Max 0.035	Impurity; controlled for machinability

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

• Core tensile strength: 650 – 850 MPa
• Core yield strength: 400 – 600 MPa
• Surface hardness (carburized): 58 – 62 HRC
• Core hardness: 170 – 210 HB
• Impact toughness: Good
• Fatigue resistance: Good

Heat treatment

• Annealing: improves machinability before carburizing.
• Carburizing: introduces carbon at high temperature to achieve a hard, wear-resistant surface.
• Quenching: rapid cooling to obtain a hard martensitic case.
• Tempering: relieves internal stresses while maintaining surface hardness and core toughness.

The heat treatment cycle can be adjusted based on required case depth and application needs.

Key features and benefits

• Good case hardening response
• Hard ware-resistant surface with tough core
• Good fatigue and impact resistance
• Good machinability in annealed condition
• Dimensional stability after heat treatment
• Suitable for forging and machining processes

Typical applications

• Gears and pinions
• Transmission and drive components
• Shafts and couplings
• Automotive and tractor parts
• General engineering components

Equivalent steel grades

16CrNi4 has several international equivalents, including:

• En 10084 – 16CrNi4
• Din 1.5714
• Bs en34 (application-based comparison)

Why choose 16CrNi4 for your application?

16CrNi4 provides a balanced combination of surface hardness, core toughness, and cost-effectiveness. It is ideal for case-hardened components operating under moderate load conditions where reliable performance and economy are required.

Comparison table for similar grades

Grade	Carbon (%)	Key applications	Heat treatment	Comments
16CrNi4	0.14 – 0.19	Gears, shafts	Carburizing + q&t	Cost-effective ni-cr steel
15CrNi6	0.12 – 0.18	Gears, transmission parts	Carburizing + q&t	Higher ni
En351	0.10 – 0.20	Automotive gears	Carburizing + q&t	Low ni
En36	0.12 – 0.18	Heavy-duty gears	Carburizing	Widely used ni-cr steel

Summary

16CrNi4 is a low carbon nickel–chromium alloy steel optimized for case hardening applications. It provides a hard, wear-resistant surface, a tough core, and consistent performance for automotive and engineering components.