Jun 21 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Applications
Introduction
The carbon content in tool steels may range from as low as 0.1% to as high as more than 1.6%, and many are alloyed with alloying elements such as vanadium, molybdenum and chromium.
The high amount of tungsten in the AISI H20 tool steel provides the maximum resistance to the softening effect of elevated temperature and offers excellent wear-resistant properties, including withstanding the washing-out effect of certain processes. The following article will provide an overview of grade H20 tool steels:
Chemical Composition
The chemical composition of H20 tool steels is outlined in the following table.
|
Element |
Content (%) |
|
Tungsten, W |
9-10 |
|
Chromium, Cr |
1.80-2.20 |
|
Vanadium, V |
0.4-0.6 |
|
Carbon, C |
0.25-0.35 |
|
Silicon, Si |
0.10-0.75 |
|
Manganese, Mn |
0.10-0.4 |
Physical Properties
The following table shows the physical properties of H20 tool steels.
|
Properties |
Metric |
Imperial |
|
Density |
7.8 g/cm3 |
0.281 lb/in3 |
Mechanical Properties
The mechanical properties of H20 tool steels are displayed in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
1110 MPa |
160991 psi |
|
Yield strength |
800 MPa |
116030 psi |
|
Young’s modulus |
180 GPa |
26106 ksi |
|
Hardness |
35-42 |
35-42 |
Thermal Properties
The thermal properties of H20 tool steels are given in the following table
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@100-250°C/212-482°F) |
13 µm/m°C |
5.956 µin/in°F |
|
Thermal conductivity (@50°C/122°F) |
15 W/mK |
104 BTU.in/hrft².°F |
Applications
The following are the list of applications of H20 tool steels:
-
Extrusion dies for long production runs
-
Hot piercing punches
-
Extrusion mandrels operated without cooling
-
Hot forging dies and inserts
-
Special structural steel for springs operating at elevated temperatures.