Cast steel 4Kh4N5M4F2 for hot pressing mold of copper M1 and aluminum alloy AK7ch

2021 ◽  
Vol 2021 (2) ◽  
pp. 54-62
Author(s):  
O. M. Sydorchuk ◽  
Keyword(s):  
Aluminum Alloy ◽  
Hot Deformation ◽  
Hot Pressing ◽  
Operating Temperature ◽  
Cast Steel ◽  
Isothermal Holding ◽  
Hardened Steel ◽  
Operating Conditions ◽  
Internal Stresses ◽  
Recrystallization Process

The mode of quenching and tempering of the investigated 4Kh4N5M4F2 steel with controlled austenitic transformation during operation is developed. The optimal temperature regime of hardening of the investigated steel is 1100 ± 5 °C and with increasing hardening temperature (above 1100 °C) the size of austenitic grain increases and the recrystallization process is intensive, which leads to a decrease in strength. It is recommended to carry out low-temperature tempering at temperatures of 190 ± 10 °C of hardened steel to reduce internal stresses. It has been established that tempering of hardened steel is necessary by cooling in the air. The optimum temperature mode of steel tempering is 590 ± 5 °C. The analysis of the structural state of the investigated steel after hardening and tempering (isothermal holding for two and four hours) is carried out. It was established that the maximum operating temperature of the die for hot pressing of copper (grade M1) can reach up to 650 °C. It is shown that the die of the studied steel is able to work at (extreme) temperature operating conditions of 625–650 °C. Heat resistance decrease (below 40 HRC) and softening occur in steel above the higher operating temperature (>650 °C). A pilot test was carried out on a die tool made of 4Kh4N5M4F2 steel (non-forging technology) for hot pressing of an aluminum alloy of the AK7ch grade, which showed the same service properties at the level of 4Kh5MF1S steel (grade H13, USA), which was subjected to ingot hot deformation (forging) with working surface nitride hardening to a depth of 300 microns. Keywords: die steel, thermal treatment, hot deformation, hardness, toughness.

Microstructure of mechanically alloyed and hot-pressed Al5CuZr2

1990 ◽  
Vol 48 (4) ◽  
pp. 970-971
Author(s):  
T. E. Mitchell ◽  
P. B. Desch ◽  
R. B. Schwarz
Keyword(s):  
Mechanical Alloying ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Rapid Quenching ◽  
Hardened Steel ◽  
Alloyed Powder ◽  
Ion Milling ◽  
Mechanical Grinding ◽  
Mechanically Alloyed ◽  
Steel Container

Al3Zr has the highest melting temperature (1580°C) among the tri-aluminide intermetal1ics. When prepared by casting, Al3Zr forms in the tetragonal DO23 structure but by rapid quenching or by mechanical alloying (MA) it can also be prepared in the metastable cubic L12 structure. The L12 structure can be stabilized to at least 1300°C by the addition of copper and other elements. We report a TEM study of the microstructure of bulk Al5CuZr2 prepared by hot pressing mechanically alloyed powder.MA was performed in a Spex 800 mixer using a hardened steel container and balls and adding hexane as a surfactant. Between 1.4 and 2.4 wt.% of the hexane decomposed during MA and was incorporated into the alloy. The mechanically alloyed powders were degassed in vacuum at 900°C. They were compacted in a ram press at 900°C into fully dense samples having Vickers hardness of 1025. TEM specimens were prepared by mechanical grinding followed by ion milling at 120 K. TEM was performed on a Philips CM30 at 300kV.

Truck Tire Operating Temperatures on Flat and Curved Test Surfaces

2005 ◽  
Vol 33 (3) ◽  
pp. 156-178 ◽  
Author(s):  
T. J. LaClair ◽  
C. Zarak
Keyword(s):  
Flat Surface ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Load Pressure ◽  
Truck Tire ◽  
Endurance Testing ◽  
Operating Temperatures ◽  
The Impact ◽  
Tread Rubber ◽  
Cylindrical Test

Abstract Operating temperature is critical to the endurance life of a tire. Fundamental differences between operations of a tire on a flat surface, as experienced in normal highway use, and on a cylindrical test drum may result in a substantially higher tire temperature in the latter case. Nonetheless, cylindrical road wheels are widely used in the industry for tire endurance testing. This paper discusses the important effects of surface curvature on truck tire endurance testing and highlights the impact that curvature has on tire operating temperature. Temperature measurements made during testing on flat and curved surfaces under a range of load, pressure and speed conditions are presented. New tires and re-treaded tires of the same casing construction were evaluated to determine the effect that the tread rubber and pattern have on operating temperatures on the flat and curved test surfaces. The results of this study are used to suggest conditions on a road wheel that provide highway-equivalent operating conditions for truck tire endurance testing.

Sliding wear evaluation of aluminum alloy (7075-T6) on hardened steel (AISI4340) via non-contact technique by I-kaz™ multi-level analysis

Wear ◽  
2015 ◽  
Vol 334-335 ◽  
pp. 99-104 ◽  
Author(s):  
Z. Karim ◽  
M.Z. Nuawi ◽  
J.A. Ghani ◽  
M.J. Ghazali ◽  
S. Abdullah ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Sliding Wear ◽  
Hardened Steel ◽  
Multi Level ◽  
Wear Evaluation ◽  
Aluminum Alloy 7075 ◽  
Level Analysis

Cast steel with adjustable austenitic transformation during operation, obtained by electroslag remelting

2020 ◽  
Vol 2020 (01) ◽  
pp. 77-85
Author(s):  
O. M. Sydorchuk ◽  
◽  
A. A. Mamonova ◽  
Y. V. Lukianchuk ◽  
K. O. Gogaiev ◽  
...  
Keyword(s):  
Heat Resistance ◽  
Uniform Distribution ◽  
Structural State ◽  
Cast Steel ◽  
Hardened Steel ◽  
The Body ◽  
Cast State ◽  
Tempering Temperature ◽  
Austenitic Transformation ◽  
Base Steel

The ligature for finishing of base steel 3H3M3Ftype for obtaining steel 4H3N5M3Ftype with adjustable austenitic transformation is developed in the article. The phase-structural state of steel in the cast state is investigated. The uniform distribution of alloying components on the body of grains is shown. It was found that the investigated hardened steel is softening above the tempering temperature of 620 °C, because the heat resistance of steel decreases (below 40 HRC). It was developed a 3H3M3F base steel ligature for steel production with adjustable austenitic transformation of 4H3N5M3F brand. Ingots (ligature of the Fe―Ni―Mo―V―Mn system) weighing 25 kg were obtained. The ligature was obtained by means of an induction furnace in a casting mold. The temperature of the metal in the furnace before release was 1550 °C. The duration of refining did not exceed 20 minutes. The phase-structural state of cast steel is studied. The uniform distribution of alloying components on the body of grains is shown, as well as the absence of coarse carbide eutectic in metal. This allows to reduce energy-intensive technological operations (diffusion annealing, forging) for the die toolsmanufacture. The presence of martensitic structure in the steel in the cast state of the investigated ingot requires the main thermal operation — annealing. It is established that incomplete annealing at a temperature of 750 ± 20 °C under the condition of partial recrystallization of the investigated steel allows to improve the mechanical processing (cutting) for the production of the die tool. It was determined that the investigated hardened steel hardens above the tempering temperature of 620 °C, because the heat resistance of steel decreases (below 40 HRC). Thus, a die tool of the investigated steel for hot deformation, capable of operating up to the temperature of 620 °C. Keywords: steel, ligature, temperature, structure, hardness.

Research of throwing areols of underground pipeline in permafrost

2021 ◽  
pp. 21-30
Author(s):  
T. S. Sultanmagomedov ◽  
◽  
R. N. Bakhtizin ◽  
S. M. Sultanmagomedov ◽  
T. M. Halikov ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Experimental Study ◽  
Finite Element ◽  
Strain State ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Loss Of Stability ◽  
Underground Pipeline ◽  
The Finite Element Method ◽  
Permafrost Thawing

Study is due to the possibility of loss of stability of the pipeline in the process of pumping a product with a positive operating temperature and the formation of thawing halos. The article presents the ways of solving the thermomechanical problem of pipeline displacement due to thawing. The rate of formation of a thawing halo is investigated depending on the initial temperatures of the soil and the pumped product. The developed monitoring system makes it possible to study the rate of occurrence of thawing halos in the process of pumping the product. An experimental study on the formation of thawing halos around the pipeline was carried out on an experimental model. A thermophysical comparative calculation of temperatures around the pipeline on a model by the finite element method has been carried out. Keywords: underground pipeline; permafrost; thawing halo; monitoring; operating conditions; stress–strain state.

Research on Combined Processing Technology of Superficial Layers Hardened Steel

2016 ◽  
Vol 841 ◽  
pp. 21-28
Author(s):  
Petrică Corabieru ◽  
Stefan Velicu ◽  
Anişoara Corabieru ◽  
Dan Dragos Vasilescu ◽  
Ionel Păunescu
Keyword(s):  
Solid State ◽  
Liquid Phase ◽  
Cooling Rate ◽  
Hold Time ◽  
Hardened Steel ◽  
Operating Conditions ◽  
Technological Parameters ◽  
Surface Layers ◽  
Durability Analysis ◽  
Machined Parts

The novelty technology lies in the fact that the hardening of the surface layers is carried out both in liquid phase and in the solid state. Technology comprises three main stages with 12 technological phases.Experimentation highlights the viability of the technological procedure. The results of tests and verifications are the basis of the analysis of combined machined parts behavior in conditions similar to the operating conditions and of the analysis of the dependence between operation behavior and durability. Analysis of the results revealed the fact that failure to technological parameters: casting temperature; hold time at high temperatures; cooling rate after microalloying in liquid phase, gives rise to possible faults of the combined treated parts.

Microstructure Evolution and Coarsening Mechanism of 7075 Semi-Solid Aluminum Alloy Pre-Deformed by ECAP Method

2016 ◽  
Vol 256 ◽  
pp. 294-300 ◽  
Author(s):  
Jin Long Fu ◽  
Yu Wei Wang ◽  
Kai Kun Wang ◽  
Xiao Wei Li
Keyword(s):  
Aluminum Alloy ◽  
Solid State ◽  
Ostwald Ripening ◽  
Liquid Fraction ◽  
Isothermal Holding ◽  
Angular Pressing ◽  
Average Grain Size ◽  
Semi Solid ◽  
Equiaxed Grains ◽  
Kinetics Of

To investigate the influence of refined grains on the microstructure of 7075 aluminum alloy in semi-solid state, a new strain induced melting activation (SIMA) method was put forward containing two main stages: pre-deformation with equal channel angular pressing (ECAP) method and isothermally holding in the semi-solid temperature range. The breaking up and growth mechanisms of the grains and kinetics of equiaxed grains coarsening during the semi-solid holding were investigated. The results showed that the average grain size after ECAP extrusion decreased significantly, e.g., microstructure with average globular diameter less than 5μm was achieved after four-pass ECAP extrusion. Obvious grain coarsening had been found during isothermal holding in the semi-solid state and the roundness of the grains increased with the increasing holding time. The proper microstructure of 66.8μm in diameter and 1.22 in shape factor was obtained under proper soaking condition (at 590°C for 15 min). Two coarsening mechanisms, namely, coalescence in lower liquid fraction and Ostwald ripening in higher liquid fraction contributed to the grain growth process.

Effect of Hexagonal Crystal Structure Anisotropy on the Selective Grain Boundary Mobility during Texture Formation and Secondary Recrystallization in Zn

2005 ◽  
Vol 495-497 ◽  
pp. 1231-1236
Author(s):  
Vera G. Sursaeva
Keyword(s):  
Grain Boundary ◽  
Secondary Recrystallization ◽  
Stress Fields ◽  
Internal Stresses ◽  
Recrystallization Process ◽  
Boundary Mobility ◽  
Texture Formation ◽  
Hexagonal Crystal ◽  
Grain Boundary Mobility ◽  
Grain Boundary Motion

Texture formation during secondary recrystallization depends on the nature of secondary recrystallization process itself. So microstructure evolution and texture development during secondary recrystallization should be discussed concurrently. The main goal of the paper is studying of the effect of internal stresses on grain boundary motion or, more generally, the interaction of grain boundaries with stress fields and the effect of deformation inhomogeniety on grain boundary mobility during secondary recrystallization. Considering transformation from normal grain growth to secondary recrystallization, the attempt was made to characterize the microstructure and to relate it to the processes of nucleation and growth of new rains. The nucleation process is heterogeneous. The data allow us to assume that the nuclei are strain free grains.

Sign in / Sign up

Export Citation Format

Share Document