Influence of Low Temperature Thermomechanical Treatment on Some Properties of High Alloy Tool Steels

1985 ◽  
Vol 107 (2) ◽  
pp. 119-126
Author(s):  
S. W. Hejmej ◽  
C. A. Brown

The modification of mechanical properties (maximum bending strength and deflection, hardness and impact strength) of tool steels whose primary alloying elements are either chromium, tungsten, tungsten and molybdenum, or chromium and molybdenum by low temperature thermomechanical treatment (LTTMT) by rolling with deformations up to 20 percent and extrusion with 60 percent deformation has been investigated. The high chromium tool demonstrated the greatest consistent improvements in strength (40 percent) and deflection (55 percent) for LTTMT over conventional heat treatment. The influence of the LTTMT process on the microstructure of the chromium and tungsten steels is investigated by fractography using a scanning electron microscope. The tungsten steel and the extrusion process yielded a finer distribution of hard particles in the ductile matrix than did the chromium steel and rolling.

2008 ◽  
Vol 591-593 ◽  
pp. 271-276 ◽  
Author(s):  
M.A. Martinez ◽  
R. Calabrés ◽  
J. Abenojar ◽  
Francisco Velasco

In this work, ultrahigh carbon steels (UHCS) obtained by powder metallurgy with CIP and argon sintered at 1150°C. Then, they were rolled at 850 °C with a reduction of 40 %. Finally, steels were quenched at 850 and 1000 °C in oil. In each step, hardness, bending strength and wear performance were evaluated. Obtained results are justified with a metallographic study by SEM. Both mechanical properties and wear resistance are highly favoured with the thermomechanical treatment that removes the porosity of the material. Moreover, final quenching highly hardens the material. The obtained material could be used as matrix for tool steels.


2012 ◽  
Vol 67 (2) ◽  
pp. 133-139
Author(s):  
B. Matijević ◽  
I. Kumić ◽  
T. Belić

2014 ◽  
Vol 631 ◽  
pp. 18-22 ◽  
Author(s):  
Junji Ikeda ◽  
Takayuki Murakami ◽  
Takayoshi Shimozono ◽  
Reiji Watanabe ◽  
Mikio Iwamoto ◽  
...  

Low temperature degradation free Zirconia toughened alumina (ZTA) has been developed. It is reported that ZTA has higher mechanical strength compared to alumina due to the stress induced transformation and spontaneously transformation of zirconia phase on some ZTA have been occurred. For achieving the higher reliability of artificial joint prosthesis alternative to alumina and other ceramic materials, it is necessary to improve and validate the both mechanical characteristics and phase stability at the same time. We evaluated that microstructure, mechanical characteristics and phase stability of newly developed ZTA (BIOCERAM®AZUL). It was confirmed that four-point bending strength and weibull modulus were extreamly high, and ZTA has higher reliability. There were no significant changes and deterioration in four-point bending strength, crystal structure and wear property with and without accelerated aging test. Newly developed ZTA not only with high mechanical characteristics but also with phase stability could be quite useful as bearing materials in artificial joints for longer clinical use.


2018 ◽  
Vol 2018 (13) ◽  
pp. 1259-1263 ◽  
Author(s):  
E. A. Marinin ◽  
A. M. Chirkov ◽  
G. N. Gavrilov ◽  
G. P. Fetisov ◽  
D. A. Chernyshov ◽  
...  

2010 ◽  
Vol 457 ◽  
pp. 404-409
Author(s):  
Setsuo Aso ◽  
Hiroyuki Ike ◽  
Ken-Ichi Ohguchi ◽  
Yoshinari Komastu ◽  
Nobuo Konishi

Particle reinforcement via the insertion of hard particles is a promising process in materials reinforcing. Particle-reinforced spheroidal graphite martensitic cast iron (SGMC), in which mixed particles of cermet and cemented carbide are dispersed, was achieved by an insertion process. A four-point bending strength test was applied to evaluate the particle composite material. An evaporative pattern process was used on the bending-test specimen to form a composite layer in the central part. Using a combination of three sizes of cermet particles and two sizes of cemented-carbide particles, the bending strength was found to increase with each small-particle combination. The Weibull coefficient m of the four-point bending strength of the particle-reinforced composite material (PRCM) ranged from 4 to 13, and m was large in the specimen with large bending strength.


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