Sep 20 2012
Topics Covered
IntroductionChemical CompositionPhysical PropertiesMechanical PropertiesOther Designations
Introduction
Mold steels are designated as group P steels according to the AISI classification system. These steels consist of one medium carbon steel and all low-carbon P-series tool steels such as P2, P3, P4, P5, P6, P20, and P21 type steels. Two major elements present in the mold steels are nickel and chromium. All the other P-series steels, except P4 and P21, have low resistance to softening at high temperatures, while P21 and P4 have medium softening resistance. These low-carbon mold steels are subjected to deep hardening.
The following section will give an overview of P5 low-carbon mold steel.
Chemical Composition
The following table shows the chemical composition of P5 tool steels.
| Element |
Content (%) |
Fe
|
95
|
| C |
0.1 |
| Mn |
0.20-0.60 |
| Si |
0.4 |
| Cr |
2.00-2.50 |
| Ni |
0.35 |
| Cu |
0.25 |
| P |
0.03 |
| S |
0.03 |
Physical Properties
The physical properties of P5 tool steels are given in the following table.
| Properties |
Metric |
Imperial |
| Density |
7.85 g/cm3 |
0.281 lb/in3 |
Mechanical Properties
The mechanical properties of P5 tool steels are tabulated below.
| Properties |
Metric |
Imperial |
| Poisson's ratio |
0.27-0.30 |
0.27-0.30 |
| Elastic modulus |
190-210 GPa |
27557-30458 ksi |
Other Designations
Other designations that are equivalent to P5 tool steels include: