scholarly journals Effects of Concentrations of Micro-alloying Elements and Hot-forging Temperature on Austenite Grain Structure Formed during Carburization of Case-hardening Steel

2020 ◽  
Vol 60 (11) ◽  
pp. 2549-2557
Author(s):  
Genki Saito ◽  
Norihito Sakaguchi ◽  
Munekazu Ohno ◽  
Kiyotaka Matsuura ◽  
Masayoshi Takeuchi ◽  
...  
Keyword(s):  
Hot Forging ◽  
Alloying Elements ◽  
Grain Structure ◽  
Case Hardening ◽  
Austenite Grain ◽  
Case Hardening Steel

scholarly journals Formation Mechanism of Coarse Austenite Grain during Hot Forging and Cooling in Case Hardening Steel

2020 ◽  
Vol 106 (2) ◽  
pp. 108-120 ◽  
Author(s):  
Takeshi Miyazaki ◽  
Takeshi Fujimatsu ◽  
Goro Miyamoto ◽  
Tadashi Furuhara
Keyword(s):  
Formation Mechanism ◽  
Hot Forging ◽  
Case Hardening ◽  
Austenite Grain ◽  
Case Hardening Steel

scholarly journals Matematical modeling of the process of enlarging the austenitic grain during high-temperature heating of alloy structural steel

2019 ◽  
pp. 74-84
Author(s):  
V. A. Kukareko ◽  
B. M. Gatsuro ◽  
A. N. Grigorchik ◽  
A. N. Chichin
Keyword(s):  
High Temperature ◽  
Heating Rate ◽  
Grain Structure ◽  
Slow Heating ◽  
Case Hardening ◽  
Regression Equations ◽  
Impurity Atoms ◽  
Average Size ◽  
Case Hardening Steel

The influence of the heating rate of a typical case hardening steel 15KHGN2TA and 25KHGT on the growth of austenitic grain during long-term isothermal exposures at the high-temperature chemical-heat treatment was studied. It is shown that the change in the rate of heating case hardening steels in the temperature interval a®g transformations during chemical-thermal treatment has a significant impact on the process of growth of austenitic grains in them.Regression equations describing the dependence of the average size of austenitic grain on the heating rate, pre-annealing temperature and cementation temperature are obtained, which allow selecting the cementation modes of various steels. A phenomenological model describing the mechanism of formation and growth of austenitic grains in steels under heating at different speeds is developed.It is concluded that the slow heating of steels in the interval of phase a®g transformation contributes to the formation of a complex of small austenite grains separated by high angle boundaries with adsorbed on them by impurity atoms, which ensures higher resistance grain structure to coalescence and reduce the rate of migration of the boundaries during prolonged hightemperature austenization.

scholarly journals Analysis of the applicability of steel 20MnCrS5 for gears of the domestic mobile machines

2020 ◽  
pp. 44-49
Author(s):  
S. P. Rudenko ◽  
A. I. Valko ◽  
S. G. Sandomirskii
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Diffusion Layer ◽  
Physical And Mechanical Properties ◽  
Virtual Simulation ◽  
Alloying Elements ◽  
Case Hardening ◽  
European Standard ◽  
Case Hardening Steel ◽  
Maximum Limit

Evaluation of applicability of 20MnCrS5 steel for gears of transmissions of mobile machines, manufactured according to European standard EN 10084 was carried out. Experimental and virtual simulation of hardenability of the steel according to the updated method was realized. The assessment of the applicability of 20MnCrS5 case-hardening steel for gears of the domestic mobile machines was made by the criterion of obtaining the cross section of the tooth structures with a hardness 32 HRC for core, 50 HRC for semi-conversion zone, 61–63 HRC for the diffusion layer excluding other physical and mechanical properties of steel.It is established that at the content of alloying elements close to the maximum limit, the use of this steel is possible for gears with a module up to 10 mm.

scholarly journals High-Temperature Precipitation Design-of-Experiments Simulation in Low-Alloy Cr–Mo–Ni Hot Forging Steel

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1054
Author(s):  
Roberto Gonzalez-Ojeda ◽  
Octavio Lozada-Flores ◽  
Gonzalo Gonzalez-Reyes ◽  
Jose Manuel Sanchez-Moreno
Keyword(s):  
Design Of Experiments ◽  
Hot Forging ◽  
Alloying Elements ◽  
Short Term ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Mns Precipitation ◽  
Austenite Grains ◽  
Deformed Bar

The role of alloying elements such as Cr, Mo and Mn on low-alloy 8620 steel during hot forging operations is not yet clear, as, during deformation in the 1000~1100 °C temperature range, the austenite grain size remains small, ensuring the capacity of the forged part to be subsequently modified by surface hardening procedures. This work analyzed a deformed bar considering hardness at different geometry zones, along with SEM and TEM microstructures of previous austenite grains and lamellar martensite spacing. Moreover, Thermocalc simulations of M7C3, M23C6 and MnS precipitation were combined with Design of Experiments (DOE) in order to detect the sensitivity and significant variables. The values of the alloying elements’ percentages were drastically modified, as nominal values did not produce precipitation, and segregation at the austenite matrix may have been responsible for short-term, nanometric precipitates producing grain growth inhibition.

AISI 4320

Alloy Digest ◽  
1959 ◽  
Vol 8 (2) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Heat Treating ◽  
Case Hardening ◽  
High Toughness ◽  
Nickel Chromium ◽  
Steel Mills ◽  
Shock Resistance ◽  
Case Hardening Steel

Abstract AISI 4320 is a nickel-chromium-molybdenum case hardening steel having high toughness and shock resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-80. Producer or source: Alloy steel mills and foundries.

AISI 8615

Alloy Digest ◽  
1965 ◽  
Vol 14 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Alloy Steel ◽  
Heat Treating ◽  
Case Hardening ◽  
Low Carbon ◽  
Heavy Duty ◽  
Core Strength ◽  
Nickel Chromium ◽  
Steel Mills ◽  
Case Hardening Steel

Abstract AISI 8615 is a low-carbon, nickel-chromium-molybdenum alloy steel capable of producing high core strength and toughness. It is a case hardening steel recommended for heavy duty gears, cams, shafts, chains, fasteners, piston pins, etc. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-180. Producer or source: Alloy steel mills and foundries.

AISI 3120

Alloy Digest ◽  
1960 ◽  
Vol 9 (4) ◽  
Keyword(s):  
Physical Properties ◽  
Tensile Properties ◽  
Alloy Steel ◽  
Heat Treating ◽  
Case Hardening ◽  
Low Carbon ◽  
Steel Mills ◽  
Shock Resistance ◽  
Case Hardening Steel

Abstract AISI 3120 is a low-carbon, chromium-nickel case-hardening steel offering good toughness and shock resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-97. Producer or source: Alloy steel mills and foundries.

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