scholarly journals THE POSSIBILITIES OF THE RETAINED AUSTENITE REDUCTION ON TOOL STEELS

2021 ◽  
Vol 6 (2) ◽  
pp. 99-105
Author(s):  
László TÓTH
Keyword(s):  
Retained Austenite ◽  
Tool Steels

Effects of Cryogenic Treatment on the Microstructure and Mechanical Properties of High-alloyed Tool Steels

2020 ◽  
Vol 75 (5) ◽  
pp. 73-93
Author(s):  
Alwin Schulz ◽  
Chengsong Cui ◽  
Matthias Steinbacher ◽  
Tuncer Ümit ◽  
Martin Wunde ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Homogeneous Distribution ◽  
Tool Steels ◽  
Positive Effects ◽  
Heat Treated ◽  
Primary Carbides ◽  
Complete Transformation

Abstract In this work, the influence of a cryogenic treatment on the microstructure, mechanical properties and wear resistance of the high-alloyed tool steels X38CrMoV5-3, X153CrMoV12 and ~X190CrVMo20-4 were investigated. Based on tempering curves of the steels, the heat treatment parameters were determined for the mechanical and wear specimens so that the conventionally heat-treated steels and the cryogenically treated steels featured similar hardness. The investigations showed that an almost complete transformation of retained austenite and a more homogeneous distribution of secondary carbides in the microstructure could be achieved by incorporating a cryogenic treatment. However, the cryogenic treatment does not show significantly positive effects on the investigated mechanical properties and wear resistance of the tool steels. The wear resistance of the samples was dominated by primary carbides. The cryogenic treatment would have a positive effect on large tool components with large wall thicknesses in terms of uniform and complete transformation of retained austenite throughout the entire components.

Tool Steels

2015 ◽  
pp. 621-645
Keyword(s):  
Wear Resistance ◽  
Phase Transformations ◽  
Retained Austenite ◽  
High Speed ◽  
Cold Work ◽  
Heat Treating ◽  
Alloy Design ◽  
Tool Steels ◽  
Evolution Of Microstructure ◽  
Alloying Principles

Tools steels are defined by their wear resistance, hardness, and durability which, in large part, is achieve by the presence of carbide-forming alloys such as chromium, molybdenum, tungsten, and vanadium. This chapter describes the alloying principles employed in various tool steels, including high-speed, water-hardening, shock-resistant, and hot and cold work tool steels. It discusses the influence of alloy design on the evolution of microstructure and properties during solidification, heat treating, and hardening operations. It also describes critical phase transformations and the effects of partitioning, precipitation, segregation, and retained austenite.

scholarly journals Retained Austenite Control for the Soft Machining of High-Hardness Tool Steels

Metals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 564 ◽  
Author(s):  
Maider Muro ◽  
Garikoitz Artola ◽  
Josu Leunda ◽  
Carlos Soriano ◽  
Carlos Angulo
Keyword(s):  
Laser Cladding ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Surface Oxidation ◽  
Aging Treatment ◽  
High Hardness ◽  
Austenite Formation ◽  
Tool Steels ◽  
Deep Cryogenic Treatment ◽  
Finish Machining

Most high-hardness tool steels comprising forming dies require expensive finish machining operations to compensate for the dimensional distortion and surface oxidation caused by the die heat treatment. Precipitation-hardening (PH) tool steels allow for soft finish machining followed by an aging treatment without major deformation or oxidation in the die, but exhibit poor wear performance owing to the lack of carbides in their structure. This drawback can be overcome by combining laser cladding technology, austenite retention, and cryogenic treatments. Hence, an alternative die manufacturing route based on laser cladding was explored. The forming surface of a modified chemistry tool steel die was subjected to cladding. The martensite finish (Mf) temperature of the steel was tuned to enhance austenite retention at room temperature. The cladded surface was then machined in a reduced-hardness condition resulting from retained austenite formation. Subsequent deep cryogenic treatment of the die favoured the retained-austenite-to-martensite transformation, thereby increasing the die hardness without major distortion or oxidation. This process combined the advantages of high-carbide-bearing tool steels and PH steels, allowing for a die with hardness exceeding 58 HRC to be finish machined at <52 HRC. Controlling the occurrence of retained austenite represents an effective strategy for achieving new manufacturing scenarios.

The Microstructures and Hardness Analysis of a New Hypereutectoid Mn-Cr-Mo-V Steel

2013 ◽  
Vol 58 (2) ◽  
pp. 563-568
Author(s):  
R. Dabrowski ◽  
E. Rozniata ◽  
R. Dziurka
Keyword(s):  
Heat Treatment ◽  
Chemical Composition ◽  
Liquid Nitrogen ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Chemical Compositions ◽  
Tool Steels ◽  
Maximum Hardness ◽  
Hypereutectoid Steel ◽  
Tempering Temperature

The results of a microstructure and hardness investigations of a new hypereutectoid Mn-Cr-Mo-V steel, imitating by its chemical composition tool steels, are presented in the paper. The microstructure as well hardness changes, caused by austenitising and tempering temperatures were assessed, for samples quenched and sub-quenched in liquid nitrogen, directly after the quenching treatment. Additionally, the influence of the tempering temperature on the volume fraction of the retained austenite was estimated. New hypereutectoid steel, after an appropriate heat treatment obtained the relevant hardness of the tools used in the cold and hot working proces. It was indicated that the steel hardness increases with the increases of the austenitising temperature. At 800ºC the hardness of the quenched samples were equal 895HV, and for the sub-quenched samples 937HV. The maximum hardness, after tempering (746HV), was found at a temperature of 520ºC. It will be possible, in future, to apply this obtained investigation results in designing chemical compositions and microstructures of the new hypereutectoid alloyed steels of properties required by their users.

scholarly journals Cryogenic treatment of tool steels: A brief review and a case report

2021 ◽  
Vol 4 (1) ◽  
pp. Manuscript
Author(s):  
Thee Chowwanonthapunya ◽  
Chaiyawat Peeratatsuwan ◽  
Manote Rithinyo
Keyword(s):  
Heat Treatment ◽  
Tool Steel ◽  
Retained Austenite ◽  
Cryogenic Treatment ◽  
Cold Treatment ◽  
Tool Steels ◽  
Deep Cryogenic Treatment ◽  
Conventional Heat Treatment ◽  
Wide Range

Tool steels used in marine industries demand for the effective approach to enhance their properties. Normally, conventional heat treatment is widely used to increase the performance of tool steels. However, this method cannot fully enhance the tool steel performance. On the other hand, cryogenic treatment is a supplementary process to the conventional heat treatment, which can promote the conversion of retained austenite to martensite and accelerate the precipitation of fine carbides. In this paper, a systematic review of cryogenic treatment of tool steels was presented. A wide range of useful investigations was reviewed, particularly in the details of the transformation of retained austenite to martensite and the precipitation of the fine carbides. A case study on a tool steel subjected to conventional heat treatment, conventional cold treatment, and deep cryogenic treatment was also given and discussed to give an insight in the cryogenic treatment of tool steels.

Sign in / Sign up

Export Citation Format

Share Document