AISI 4150 Alloy Steel (UNS G41500)

Topics Covered

Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
     Machinability
     Forming
     Welding
     Heat Treatment
     Forging
     Hot Working
     Cold Working
     Annealing
     Tempering
     Hardening


Introduction

Alloy steels are designated by AISI four-digit numbers. They comprise different kinds of steels having compositions exceeding the limitations of B, C, Mn, Mo, Ni, Si, Cr, and Va set for carbon steels.

AISI 4150 alloy steel is a higher carbon variation of chromium, manganese, molybdenum 4100 low alloy steel. The following datasheet gives an overview of AISI 4150 alloy steel.

Chemical Composition

The following table shows the chemical composition of AISI 4150 alloy steel.

Element Content (%)
Iron, Fe 96.745 - 97.67
Chromium, Cr 0.800 - 1.10
Manganese, Mn 0.750 - 1.00
Carbon, C 0.480 - 0.530
Silicon, Si 0.150 - 0.300
Molybdenum, Mo 0.150 - 0.250
Sulfur, S  0.0400
Phosphorous, P  0.0350

Physical Properties

The physical properties of AISI 4150 alloy steel are given in the following table.

Properties Metric Imperial
Density 7.85 g/cm3 0.284 lb/in³
Melting point 1427°C 2600°F

Mechanical Properties

The following table outlines the mechanical properties of annealed AISI 4150 alloy steel.

Properties Metric Imperial
Tensile strength 731 MPa 106000 psi
Yield strength 380 MPa 55100 psi
Izod Impact 24 J 17.7 ft-lb
Bulk modulus (typical for steel) 140 GPa 20300 ksi
Shear modulus (typical for steel) 80 GPa 11600 ksi
Elastic modulus 190-210 GPa 27557-30458 ksi
Poisson's ratio 0.27-0.30 0.27-0.30
Elongation at break (In 50 mm) 20.20% 20.20%
Reduction of area 40% 40%
Hardness, Brinell 197 197
Hardness, Knoop (converted from Brinell hardness) 219 219
Hardness, Rockwell B (converted from Brinell hardness) 92 92
Hardness, Rockwell C (converted from Brinell hardness. Value below normal HRC range, for comparison purposes only) 13 13
Hardness, Vickers (converted from Brinell hardness) 207 207
Machinability (annealed and cold drawn; based on AISI 1212 as 100 machinability) 55 55

Thermal Properties

The thermal properties of AISI 4150 alloy steel are highlighted in the following table.

Properties Metric Imperial
Thermal conductivity (typical steel) 44.5 W/mK 309 BTU in/hr.ft².°F

Other Designations

Other designations that are equivalent to AISI 4150 alloy steel include:

  • ASTM A29 (4150)
  • ASTM A322 (4150)
  • ASTM A331 (4150)
  • ASTM A519 (4150)
  • ASTM A711
  • ASTM A752 (4150)
  • MIL S-11595 (ORD4150)
  • SAE J1397 (4150)
  • SAE J404 (4150)
  • SAE J412 (4150)

Fabrication and Heat Treatment

Machinability

AISI 4150 alloy steel has good machinability in annealed or normalized conditions.

Forming

AISI 4150 alloy steel has good formability and ductility in the annealed condition.

Welding

AISI 4150 alloy steel can be welded using all conventional techniques. The mechanical properties of this steel can be affected if it is welded in the hardened condition. Post-weld heat treatment should be performed followed by an approved welding procedure

Heat Treatment

AISI 4150 alloy steel can be normalized at 899°C (1650°F) before heat treatment. It is then heated at 816°C (1500°F) followed by quenching in water in order to harden the steel.

Forging

AISI 4150 alloy steel is forged at 983 to 1205°C (1800 to 2200°F).

Hot Working

AISI 4150 alloy steel is hot worked at 872 to 1038°C (1600 to 1900°F)

Cold Working

AISI 4150 alloy steel is cold worked using conventional methods in the annealed condition.

Annealing

AISI 4150 alloy steel is annealed at 899°C (1650°F) followed by slowly cooling in the furnace.

Tempering

AISI 4150 alloy steel is tempered at 205 to 649°C (400 to 1200°F) based on the desired hardness level. The hardness of this steel can be reduced if the tempering temperature is higher.

Hardening

AISI 4150 alloy steel can be hardened by cold working or by heat treatment and tempering.

Date Added: Sep 7, 2012 | Updated: Jul 11, 2013
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