Maraging steel 18Ni300 is one of the most widely used type of maraging steels. It is a high-strength steel known for its good ductility and resistance to crack propagation.
In the thesis, we analyzed the influence of aging temperature on the thermal and electrical conductivity (resistivity) change during precipitation hardening of maraging steel 18Ni300 (W.nr. 1.2709). All measurements of thermal properties were performed using the transient plane source method (TPS 2200 Hot Disk ®) in accordance with the ISO 22007-2 standard. The sequence of precipitation was monitored through in-situ measurements of electrical resistivity (four-wire method) during heating. We addressed and measured thermal properties such as thermal conductivity, temperature conductivity, and volumetric specific heat, and how temperature and time of aging influence their values. determined the relationship between electrical and thermal conductivity, as well as whether the occurrence of reverse austenite can be determined based on the measurements of electrical and thermal conductivity. We also found out whether it is possible to determine the occurrence of reverse austenite using the method of in-situ measurement of electrical resistance change. After each heat treatment, the Rockwell hardness of the material was also measured.
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