Hot‐work tool steels represent a group of steels which are used for metal forming operations at elevated temperatures, e. g. die casting, extrusion molding and drop forging. During application such working tools are exposed for a short time to both high temperatures and mechanical stresses. Short‐term creep tests of two chromium rich martensitic hot‐work tool steels which basically differ in their molybdenum, carbon and silicon content were conducted at temperatures in the range of 540°C to 600°C and at stress levels ranging from 280 MPa to 600 MPa. Both steels showed a minimum strain rate, at approximately 1/6 time to rupture, instead of a steady‐state creep range. The stress exponents of both steels indicate dislocation creep as the dominant creep mechanism. Microstructural investigations showed that in both steels the secondary hardening carbides are type of MC and M2C. A higher content of molybdenum and carbon causes a higher volume fraction of these carbides and results in a better short‐term creep behavior.
[1]
H. Clemens,et al.
Short-term creep behavior of a Cr Mo V hot-work tool steel
,
2009
.
[2]
M. Panzenböck,et al.
Zum Kurzzeitkriechverhalten von Warmarbeitsstählen
,
2008
.
[3]
F. Abe,et al.
Creep characteristics in carbon free new martensitic alloys
,
2005
.
[4]
M. Mathon,et al.
Influence of silicon content on the precipitation of secondary carbides and fatigue properties of a 5%Cr tempered martensitic steel
,
2005
.
[5]
Gunther Eggeler,et al.
The evolution of dislocation density during heat treatment and creep of tempered martensite ferritic steels
,
2003
.
[6]
H. Berns,et al.
Das Kriechverhalten von Warmarbeitsstählen mit 5% Chrom
,
1980
.