AISI 1018 Carbon Steel (UNS G10180)Topics
CoveredIntroduction
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
Applications
IntroductionThere are many different categories of steel, and
carbon steels are one such category that contains 0.12 to 2% carbon
in them. The
steel gains hardness and strength with heat treatment when the
carbon percentage content increases; however its ductility is
reduced.
AISI 1018 carbon steel is a free machining grade that is the
most commonly available grade around the world. Although its
mechanical properties are not very unique, it still can be
easily formed, machined, welded and fabricated.
The following sections will discuss in detail about AISI 1018
carbon steel.
Chemical CompositionThe chemical composition of AISI 1018 carbon
steel is outlined in the following table.
Element Content (%)
Manganese, Mn 0.60-0.90
Carbon, C 0.15-0.20
Sulfur, S 0.05 (max)
Phosphorous, P 0.04 (max)
Iron, Fe Balance
Physical PropertiesThe physical properties of AISI 1018 carbon
steel are tabulated below.
Properties Metric Imperial
Density 7.87 g/cm3 0.284 lb/in3
Mechanical PropertiesThe following table shows mechanical
properties of cold drawn AISI 1018 carbon steel.
Properties Metric Imperial
Tensile strength 440 MPa 63800 psi
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Yield strength 370 MPa 53700 psi
Modulus of elasticity 205 GPa 29700 ksi
Shear modulus (typical for steel) 80 GPa 11600 ksi
Poissons ratio 0.29 0.29
Elongation at break (in 50 mm) 15% 15%
Hardness, Brinell 126 126
Hardness, Knoop (converted from Brinell hardness) 145 145
Hardness, Rockwell B (converted from Brinell hardness) 71 71
Hardness, Vickers (converted from Brinell hardness) 131 131
Machinability (based on AISI 1212 steel. as 100 machinability)
70 70
Thermal PropertiesThe thermal properties of AISI 1018 carbon
steel are given in the following table.
Properties Metric Imperial
Thermal conductivity 51.9 W/mK 360 BTU in/hr.ft2.F
Other DesignationsOther designations that are equivalent to AISI
1018 carbon steel include the following.
AMS 5069 ASTM A29 ASTM A512 ASTM A611 (D-1) ASTM A635
AMS 5069A ASTM A510 ASTM A794 ASTM A519 ASTM A544
ASTM A108 ASTM A513 ASTM A830 ASTM A545 ASTM A548
ASTM A549 ASTM A659 SAE J412 SAE J1397 MIL S-11310 (CS 1018)
ASTM A576 SAE J403 SAE J414 MIL J-1397 MIL J-403
MIL J-412
Fabrication and Heat Treatment
MachinabilityAISI 1018 carbon steel is rated at 62% of AISI 1112
carbon steel. Machining provides this alloy with a fine finish,
with continuous and
hard chips. It is possible to machine this alloy in all
conditions.
FormingIt is easy to form AISI 1018 carbon steel in the annealed
condition.
WeldingAISI 1018 carbon steel can be welded using most of the
conventional methods such as gas, oxyacetylene, resistance, and
submerged melt welding.
Heat TreatmentAISI 1018 carbon steel can be case hardened to Rc
42, but only in thin sections. In case of thicker sections of over
4 in., Rc 28-30
can be obtained.
ForgingForging of AISI 1018 carbon steel can take place in the
range of 996-1260C (1825-2300F).
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Hot WorkingAISI 1018 carbon steel can be easily hot worked.
Cold WorkingCold working AISI 1018 carbon steel will affect the
hardness and mechanical properties. Intermediate annealing has to
be performed
to overcome the alloys tendency to work harden.
AnnealingComplete annealing of this alloy can be achieved by
soaking at 899C (1650F) followed by furnace cooling. Process
annealing can
be done at 649C (1200F).
ApplicationsAISI 1018 carbon steel is commonly used in high
volume screw machine parts applications. The other applications of
this alloy are as
follows:
Shafts
Spindles
Pins
Rods
Sprocket assemblies.
Date Added: Jun 7, 2013 | Updated: Jun 17, 2013
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