YMT S131R is a plastic mold steel, which has better hardenability than the commonly used 1.2738. The addition of elemental vanadium (V) increases the working hardness of the material and improves the resistance to tempering. YMTS131R means uniform hardness distribution with improved machinability, improved polishability, and is more suitable for texturing.
For better polishing results, ESR grade YMT S131R is recommended.
Chemical Composition (%)
Steel grade (%) |
C |
Si |
Mn |
Cr |
Mo |
Ni |
V |
YMT S131R |
~0.28 |
~MAX 0.30 |
~1.50 |
~1.50 |
~0.50 |
~1.10 |
~0.15 |
Applications
Typical applications are for the manufacture of injection molds, especially for the manufacture of large plastic injection molds in different industrial sectors.
Hardness Range
YMT S131R: 36-41HRC / 1050-1220N/mm²
Physical Property
Modulus of Elasticity [103x N/mm2]: 205
Density[g/cm3]: 7.80
Specific Heat Capacity [J/Kg.K]: 460
Thermal Conductivity [W/m.K]:
20 °C |
100 °C |
200 °C |
300 °C |
400 °C |
500 °C |
600 °C |
700 °C |
38.9 |
38.7 |
38.3 |
39 |
39.8 |
38.9 |
37.9 |
32.6 |
Coefficient of Linear Thermal Expansion 10-6°C-1
20-100 °C |
20-200 °C |
20-300 °C |
20-400 °C |
20-500 °C |
20-600 °C |
20-270 °C |
11.7 |
12.3 |
13.0 |
13.3 |
13.7 |
13.7 |
14.0 |
Stress Relief
To eliminate the stress caused by machining, the heating temperature must be about 650°C . For pre-hardened materials, the relief stress of machining is eliminated by heating to approximately 550°C.
Forging Temperature: 1100-950 OC
Soft Annealing
Heated to 710-740 °C, slowly cooled with the furnace, annealing hardness max.235HB
Quenching
Heated to austenitizing temperature 860-880 °C, then quenched in oil, synthetic polymer quenching liquid or vacuum furnace, quenching hardness of about 52HRC.
Tempering/Hardness/UTS
Temp |
20 °C |
100 °C |
200 °C |
300 °C |
400 °C |
500 °C |
600 °C |
700 °C |
HRC |
52 |
51.5 |
50.5 |
49.5 |
47.5 |
45 |
38 |
25 |
N/mm2 |
1790 |
1760 |
1700 |
1650 |
1550 |
1440 |
1200 |
850 |
Non-metallic Inclusion
As per ASTM E45 method A
At ≤1.5, Bt≤l.5, Ct≤l.5, Dt≤l.5; Ad≤1,5, Bd≤l.5, Cd≤1.5, Dd≤l.5 or DIN50602 or subject to customer's
requirements.