Effect of Heat Treatment on the Structure and Properties of the Carburized Layer of the Legs of Three-Ball Drill Bits

2021 ◽  
Vol 410 ◽  
pp. 554-559
Author(s):  
Olga N. Petrova ◽  
Sergey V. Belikov ◽  
Yuri V. Slukin
Keyword(s):  
Heat Treatment ◽  
Retained Austenite ◽  
Minimal Amount ◽  
Structure And Properties ◽  
Carbide Network ◽  
The Core ◽  
Carburized Steel ◽  
Drill Bits ◽  
Carburized Layer ◽  
Martensite Structure

The effect of time-temperature parameters of heat treatment on the structure and properties of carburized case and the core of 19CrMnNiMo steel was studied. The critical points were determined by dilatometric analysis: Ac1 = 740°C, AC3 = 835°C. It was established, that after carburizing at 940 °C, prequench to 890 °C with oil cooling, quenching at 790 °C and tempering at 180 °C, martensite structure of carburized case with uniformly distributed carbides and the least amount of retained austenite is formed. The hardness of carburized case decreases smoothly from the surface into the depth, in proportion to the decrease in the carbon concentration and amounts to 60-50 HRC. The technological process of heat treatment of drill bit legs made of 19CrMnNiMo carburized steel providing minimal amount of retained austenite in structure, absence of carbide network and combination of optimum mechanical properties which is proved by a real on-site experiment is developed. Temperature conditions of carburizing, quenching and low tempering are recommended for the production of legs of roller bits.

scholarly journals Assessment of Retained Austenite in Fine Grained Inductive Heat Treated Spring Steel

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4063 ◽  
Author(s):  
Anna Olina ◽  
Miroslav Píška ◽  
Martin Petrenec ◽  
Charles Hervoches ◽  
Přemysl Beran ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cross Section ◽  
Retained Austenite ◽  
Quantitative Assessment ◽  
Spring Steel ◽  
Rapid Phase ◽  
Fine Grained ◽  
The Core ◽  
Heat Treated

Advanced thermomechanical hot rolling is becoming a widely used technology for the production of fine-grained spring steel. Different rapid phase transformations during the inductive heat treatment of such steel causes the inhomogeneous mixture of martensitic, bainitic, and austenitic phases that affects the service properties of the steel. An important task is to assess the amount of retained austenite and its distribution over the cross-section of the inductive quenched and tempered wire in order to evaluate the mechanical properties of the material. Three different analytical methods were used for the comparative quantitative assessment of the amount of retained austenite in both the core and rim areas of the sample cross-section: neutron diffraction—for the bulk of the material, Mössbauer spectroscopy—for measurement in a surface layer, and the metallographic investigations carried by the EBSD. The methods confirmed the excessive amount of retained austenite in the core area that could negatively affect the plasticity of the material.

Carburizing

1999 ◽  
Author(s):  
Geoffrey Parrish
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Impact Toughness ◽  
Fracture Strength ◽  
Retained Austenite ◽  
Nonmetallic Inclusions ◽  
Print Version ◽  
The Core ◽  
Carburized Steel ◽  
Fatigue And Fracture

Carburizing: Microstructures and Properties explains how to recognize and address problems associated with case carburizing treatments for steels. It examines the nature of internal oxidation, decarburization, free carbides, and retained austenite and their effect on fatigue and fracture strength, wear resistance, impact toughness, hardness, and other properties. It discusses the influence of grain size, microcracking, microsegregation, and nonmetallic inclusions and explains how composition and cooling rate determine the core properties of carburized steel parts and how alloy and carbon content largely determine the depth and hardness of the case. It also discusses the effect of tempering, refrigeration, grinding, roller burnishing, and shot peening, and makes extensive use of images, graphs, charts, and examples throughout. For information on the print version, ISBN 978-0-87170-666-9, follow this link.

The Structure and Properties of Carburized and Hardened Vanadium Microalloyed Steels

2009 ◽  
Vol 83-86 ◽  
pp. 1270-1281
Author(s):  
Md. Mohar Ali Bepari ◽  
Md. Nizamul Haque ◽  
Kazi Md. Shorowordi
Keyword(s):  
Retained Austenite ◽  
Surface Hardness ◽  
Carbon Steels ◽  
Microalloyed Steels ◽  
Structure And Properties ◽  
Low Carbon ◽  
Austenite Grain Size ◽  
Hardened Steels ◽  
The Core ◽  
Core Hardness

Three 0.15% carbon steel samples containing small additions of vanadium and nitrogen singly or in combination have been carburized in a natural Titas gas atmosphere at a temperature of 9500C and a pressure of about 15 psia for time periods ranging from 1 to 5 hours and quenched in 10% brine from the carburizing temperature of 9500C after pre-cooling to 8600C in the furnace followed by tempering at a low temperature of 1600C. The structure and properties of the carburized and heat treated specimens were studied systematically by optical microscopy, surface hardness and microhardness measurements, X-ray diffractometry and impact tests. It was found that vanadium without nitrogen does not have any effect in the formation of retained austenite while vanadium with nitrogen is effective in promoting the formation of retained austenite in the case of carburized and hardened steels. It was also found that vanadium alone and vanadium with nitrogen refine the martensite platelets (needles) in the case of carburized and hardened steels, vanadium with nitrogen being more effective. Microhardness measurements have shown that vanadium improves the case hardness and the core hardness values; vanadium with nitrogen is more effective than vanadium alone in increasing the case hardness and the core hardness. The hardenability is found to increase with the increase of austenite grain size and with the extent of carbon penetration of the case of carburized steels. Vanadium as vanadium carbide, VC are detrimental to toughness and vanadium as vanadium carbonitride, V(C, N) are beneficial to toughness of the core of low carbon steels in carburized and hardened condition.

Study on the Grinding Machinability of 9Mn2V under Different Heat Treatment Processes

2014 ◽  
Vol 1017 ◽  
pp. 114-119
Author(s):  
Guo Qiang Guo ◽  
Ying Juan Mu ◽  
Chang Qi Yang ◽  
Zhong Quan Li ◽  
Ying Tian ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Retained Austenite ◽  
Second Grade ◽  
Material Structure ◽  
Workpiece Material ◽  
Carbide Network ◽  
Treatment Processes ◽  
Grinding Performance ◽  
Tempering Treatment ◽  
The Relationship

The relationship between heat treatment processes and grinding performance of cold die steel 9Mn2V had been built in this paper. Serious meshy segregation of carbide, excessive amounts of retained austenite, coarse and inhomogeneous distribution of material structure were significant causes of grinding burn and grinding crack. In order to improve the abrasion-resistance and mechanical properties of workpiece material, cryogenic and tempering treatment were added. Disappear of meshy segregation of carbide, network carbide was within second grade, retained austenite content was within 4%, martensite became much more fine and homogeneous, all of these advantages could be obtained by adopting cryogenic and tempering treatment in twice. The grinding experiment results indicated that workpiece material 9Mn2V which using this process could provide superior grinding performance.

The Effects of Quenching and Tempering Treatment on the Hardness and Microstructures of a Cold Work Steel

2019 ◽  
Vol 4 (1) ◽  
pp. 286-294
Author(s):  
László Tóth ◽  
Réka Fábián
Keyword(s):  
Heat Treatment ◽  
Retained Austenite ◽  
Elevated Temperatures ◽  
Cryogenic Treatment ◽  
Cold Work ◽  
Chromium Steel ◽  
Primary Carbide ◽  
Tempering Temperature ◽  
Tempering Treatment ◽  
Primary Carbides

The X153CrMoV12 ledeburitic chromium steel characteristically has high abrasive wear resistance, due to their high carbon and high chromium contents with a large volume of carbides in the microstructure. This steel quality has high compression strength, excellent deep hardenability and toughness properties, dimensional stability during heat treatment, high resistance to softening at elevated temperatures. The higher hardness of cryogenic treated samples in comparison with conventional quenched samples mean lower quantity of retained austenite as at samples quenched to room temperature and tempered in similar condition. In the microstructure of samples were observed that the primary carbide did not dissolve at 1070°C and their net structure have not been changed during to heat treatment. During to tempering at high temperature the primary carbides have become more and more rounded. After low tempering temperature in martensite were observed some small rounded carbides also, increasing the tempering temperature the quantity of finely dispersed carbides increased, which result higher hardness. The important issues in heat treatment of this steels are the reduction or elimination of retained austenite due to cryogenic treatment.

Heat Treatment Effects on Distortion, Residual Stress, and Retained Austenite in Carburized 4320 Steel

2014 ◽  
Vol 783-786 ◽  
pp. 692-697 ◽  
Author(s):  
Andrew Clark ◽  
Randy J. Bowers ◽  
Derek O. Northwood
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Retained Austenite ◽  
Compressive Residual Stress ◽  
Surface Residual Stress ◽  
Depth Profiles ◽  
Size And Shape ◽  
Austenite Content ◽  
Treatment Conditions ◽  
The Difference

The effects of heat treatment on distortion, residual stress, and retained austenite were compared for case-carburized 4320 steel, in both the austempered and quench-and-tempered condition. Navy C-ring samples were used to quantify both size and shape distortions, as well as residual stress. The austempering heat treatment produced less distortion and a higher surface residual stress. Both hoop and axial stresses were measured; the difference between them was less than seven percent in all cases. Depth profiles were obtained for residual stress and retained austenite from representative C-ring samples for the austempered and quench-and-tempered heat treatment conditions. Austempering maintained a compressive residual stress to greater depths than quench-and-tempering. Quench-and-tempering also resulted in lower retained austenite amounts immediately beneath the surface. However, for both heat treatments, the retained austenite content was approximately one percent at depths greater than 0.5 mm.

Changes in the structure and properties produced in polyester yarn by the heat treatment in the texturing process

1973 ◽  
Vol 4 (2) ◽  
pp. 179-181 ◽  
Author(s):  
L. P. Sebina ◽  
V. A. Usenko ◽  
B. A. Nefedov ◽  
V. K. Smirnov
Keyword(s):  
Heat Treatment ◽  
Structure And Properties ◽  
Polyester Yarn

The effect of heat-treatment temperature on structure and properties of TiB2/C composites

Carbon ◽  
2007 ◽  
Vol 45 (6) ◽  
pp. 1200-1211 ◽  
Author(s):  
Changjun Zhou ◽  
William S. Kinman ◽  
Paul J. McGinn
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Structure And Properties

The structure and properties of sheets from the new alloy V-1381 of the Al – Mg – Si system

2021 ◽  
Vol 5 ◽  
pp. 18-27
Author(s):  
A. A. Selivanov ◽  
◽  
K. V. Antipov ◽  
Yu. S. Oglodkova ◽  
A. S. Rudchenko ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Arc Welding ◽  
Structure And Properties ◽  
Strengthening Phase ◽  
Critical Rate ◽  
Corrosion Properties ◽  
Β Phase ◽  
Mechanical And Corrosion Properties ◽  
20 Nm ◽  
6Xxx Series

The results of the development of a new alloy of the Al – Mg – Si system of the 6xxx series, which received the V-1381 grade, are presented. The influence of the composition and modes of heat treatment on the mechanical and corrosion properties of sheets with a thickness of 1,0 and 3,0 mm, manufactured under the conditions of FSUE “VIAM”, was investigated. Average level of sheet properties: UTS = 410 MPa, YTS = 360 MPa, El = 11.5 %; fatigue crack growth (dl/dN) = 0,59 mm/kcycle at ΔK = 18,6 MPa·m1/2, intergranular corrosion ≤ 0,15 mm, exfoliation corrosion 4 points. It was found that the structure of the sheets is recrystallized, the main strengthening phase is the coherent matrix β’(Mg2Si)-phase evenly distributed in the volume of grains with a high density. There is also a heterogeneous origin of β′-phase on dislocations and dispersoids. At grain boundaries there are zones free from emissions with a width of 15 – 20 nm. Dispersoids of various morphologies are observed in the tested samples. Temperature and heat values of phase transformations in ingots and sheets are determined and established liquidus and solidus points. The sheet weldability was evaluated by automatic argon-arc welding and the critical rate of deformation of the weld metal during crystallization was determined, at which no cracks were formed in it. Laser welding mode has been developed to ensure optimal formation of geometric parameters of the weld.

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