INFLUENCE OF COOLING RATE DURING QUENCHING ON IMPACT TOUGHNESS OF A HOT-WORK TOOL STEEL AT AMBIENT TEMPERATURE AND AT 200 °C
Journal Title: Materials Engineering - Materialove inzinierstvo (MEMI) - Year 2013, Vol 20, Issue 3
Abstract
Gross cracking of die-casting dies with inferior toughness sometimes occurs through too low preheating temperature and/or too slow cooling during quenching. This study aimed to clarify the influence of cooling rate on the toughness of the hot-work tool steel grade Uddeholm Vidar Superior at ambient temperature and at 200 °C, a typical preheating temperature for aluminium die-casting dies. Toughness was measured through instrumented Charpy V-notch impact testing. The decrease in energy absorption with increasing cooling time between 800 °C and 500 °C at both ambient temperature and 200 °C was pronounced. At ambient temperature, the decrease in total energy was a consequence of a decrease in initiation energy whereas, at 200 °C, the decrease in total energy was due to a decrease in propagation energy. The present investigation does not explain the decrease in toughness with increasing cooling time between 800 °C and 500 °C. This can only be revealed by studying the metallographic structure by light microscope, scanning electron microscope, and transmission electron microscope.
Authors and Affiliations
Henrik Jesperson
Keywords
Related Articles
- EP ID EP104032
- DOI -
- Views 105
- Downloads 0
MICROSTRUCTURE AND MECHANICAL PROPERTIES DEGRADATION OF CrMo CREEP RESISTANT STEEL OPERATING UNDER CREEP CONDITIONS
In this contribution microstructure degradation of a steam tube is analysed. The tube is made of CrMo creep resistant steel and was in service under creep conditions at temperature 530°C and calculated stress level in th...
AN APPARATUS OF INCREASED PRECISION FOR THE MEASUREMENT OF ELECTRO-OPTICAL PARAMETERS OF LIQUID CRYSTALS
The ferroelectric liquid crystals (FLCs) are demanding high attention now a day, because of their potential applications in many electro-optical devices, particularly in displays. The suitable applications of FLCs in dev...
Thermal stability of magnesium alloy AZ91 prepared by severe plastic deformation
This paper deals with the thermal stability of ultrafine-grained alloy AZ91 prepared by means of ECAP (Equal Channel Angular Pressing) method. Annealing experiments were conducted isochronally for 30 minutes in the tempe...
MICROSTRUCTURE EVOLUTION OF PURE TITANIUM DURING ECAP
The main goal of the presented paper was to describe deformation behaviour of the commercial purity titanium during the ECAP method. Attention was paid particularly on reached mechanical properties of above mentioned mat...
Modeling the damage of welded steel, using the GTN model
The aim of our work is the modeling of the damage in the weld metal according to the finite element method and the concepts of fracture mechanics based on local approaches using the code ABAQUS calculates. The use of the...