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.

scholarly journals INFLUENCE OF HEAT TREATMENT ON DIE STEEL 4Kh4N5М4F2 AND ESTABLISHMENT OF ITS PHYSICAL AND MECHANICAL PROPERTIES

2021 ◽  
pp. 34-38
Author(s):  
Oleh Sydorchuk
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Service Life ◽  
Impact Strength ◽  
Cast Steel ◽  
Hardened Steel ◽  
Specific Electrical Conductivity ◽  
Tempering Temperature ◽  
Temperature Mode

The results of researches after heat treatment (hardening and tempering) of alloyed structural steel of grade 4Kh4N5М4F2 in cast and forged state are given. It is recommended to carry out partial recrystallization (incomplete annealing) of the experimental steel (4Kh4N5М4F2) at a temperature of 750±20 °С. It is recommended to carry out thermo-deformation treatment (forging at a temperature of 1170±20 °C), which doubled the grain yield of hardened steel and increased the toughness five times after tempering. The optimal temperature mode of hardening (1095±5 °С) of cast and forged steel, the hardness of which coincides at the level of 56 HRC, is established. The grain score in cast and forged state (№ 3–№ 6 and № 6–№ 8, respectively) of the investigated steel depending on the quenching temperature (1050–1110 °С) is shown. The dependence between hardness and specific electrical conductivity of steel after hardening in comparison with cast and forged state is established. It is established that at optimized modes of heat treatment of the investigated steel it was determined by the minimum value of the parameter – specific electrical conductivity. Thus, for the optimal value of the tempering temperature of steel (1095 ºC), the specific electrical conductivity was 0,075 Ohm•mm2/ m, and at tempering (595 ºC) – 0,0415 Ohm•mm2/m. The methodical approach after hardening of steel is offered that allows carrying out control of a temperature mode at heating of the stamp tool. It is established that after hardening of steel, forged has the highest conductivity than cast. Physico-mechanical properties (strength threshold, impact strength, hardness, microhardness in the metal structure and specific electrical conductivity) of the investigated hardened steel (cast and forged) after tempering are presented. An increase in the hardness and strength of cast steel during tempering at temperatures from 450 to 500 °C, which is provided by the release of the carbide component, where there is an intensive increase in microhardness. It was found that the tempering brittleness of the investigated steel at a temperature of 475±15 °C. An anomalous decrease in impact strength (up to 15 J/cm2) and an intensive increase in the specific electrical conductivity of cast and forged steel at tempering brittleness are shown. The increase of microhardness of the investigated steel is established, which promotes increase of wear resistance and increase of service life of the stamping tool. It is established that during reheating (tempering), the conductivity in steel increases, and the structurally sensitive mechanical characteristic (impact strength) changes intensively, which increases twice in the range of tempering brittleness temperatures of 475±15 ºС. This makes it possible to increase the service life of the press tool (die) made of steel 4Kh4N5M4F2 for hot deformation of aluminum alloy in the temperature range 450-500 °C.

scholarly journals Wear Resistance of TiC Reinforced Cast Steel Matrix Composite

2017 ◽  
Vol 17 (1) ◽  
pp. 143-146 ◽  
Author(s):  
S. Sobula ◽  
E. Olejnik ◽  
T. Tokarski
Keyword(s):  
Wear Resistance ◽  
Matrix Composite ◽  
Base Alloy ◽  
Cast Steel ◽  
Composite Layer ◽  
Wear Loss ◽  
Steel Matrix ◽  
Soft Matrix ◽  
Base Steel ◽  
The Matrix

Abstract Wear resistance of TiC-cast steel metal matrix composite has been investigated. Composites were obtained with SHSB method known as SHS synthesis during casting. It has been shown the differences in wear between composite and base cast steel. The Miller slurry machine test were used to determine wear loss of the specimens. The slurry was composed of SiC and water. The worn surface of specimens after test, were studied by SEM. Experimental observation has shown that surface of composite zone is not homogenous and consist the matrix lakes. Microscopic observations revealed the long grooves with SiC particles indented in the base alloy area, and spalling pits in the composite area. Due to the presence of TiC carbides on composite layer, specimens with TiC reinforced cast steel exhibited higher abrasion resistance. The wear of TiC reinforced cast steel mechanism was initially by wearing of soft matrix and in second stage by polishing and spalling of TiC. Summary weight loss after 16hr test was 0,14÷0,23 g for composite specimens and 0,90 g for base steel.

Research on Distribution Regularity of Nano-Sized WC in Cast Steel

2014 ◽  
Vol 668-669 ◽  
pp. 52-55
Author(s):  
Yang Han ◽  
Ai Ling Zhang ◽  
Lin Yang ◽  
Ya Ling Han
Keyword(s):  
Wear Resistance ◽  
Uniform Distribution ◽  
Cast Steel ◽  
Experimental Results ◽  
Steel Matrix ◽  
Gravity Segregation ◽  
Resistance Alloy ◽  
Segregation Phenomenon

The microstructure of 40CrNi2Mo steel matrix strengthened with wear resistance alloy is observed by the optical scope, SEM with EDS and FESEM. Analysis emphasis is lied on the distribution regulation of nanosized WC particulates in the microstructure of the steel matrix. Experimental results show that the method of adding wear resistance alloy in steel matrix can avoid gravity segregation phenomenon effectively and guarantee a uniform distribution of WC in steel matrix. nanosized WC particulates distributing evenly in steel matrix improve the wear resistance, and make microstructure of the steel matrix more uniform, finer and denser proved by its high-expansion micrograph.

Structural Performance Comparison between 980MPa Generation 3 Steel and Press Hardened Steel Applied in the Body-in-White A and B-Pillar Parts

2020 ◽  
Author(s):  
Vasant Pednekar ◽  
Andre Pereira ◽  
Adam Ballard ◽  
Guofei Chen ◽  
Rajmouli Komarivelli ◽  
...  
Keyword(s):  
Hardened Steel ◽  
Performance Comparison ◽  
The Body ◽  
Structural Performance ◽  
Body In White

Microstructural Investigation of the Ferritic GX12CrMoVNbN9-1 (GP91) Cast Steel

2012 ◽  
Vol 186 ◽  
pp. 287-291 ◽  
Author(s):  
Grzegorz Golański ◽  
Paweł Wieczorek
Keyword(s):  
Dislocation Density ◽  
Cast Steel ◽  
Lath Martensite ◽  
High Angle ◽  
Cast State ◽  
Tempered Martensite ◽  
Microstructural Investigation ◽  
High Chromium ◽  
Austenite Grains ◽  
Quenching And Tempering

The paper presents research on the microstructure of high chromium martensitic GX12CrMoVNbN9-1 (GP91) cast steel. The steel was subject to investigation in the as-cast state, after hardening as well as after quenching and tempering. The microstructure and morphology of precipitates in GP91 cast steel was examined in terms of changes taking place during the technological process. It has been shown that the examined cast steel is characterized by a microstructure of lath martensite (and polygonized ferrite) with numerous precipitates, such as: M3C, M23C6 and MX (NbC, VX) of diverse morphology. Tempered martensite in the cast steel consists of former austenite grains separated by high angle grain boundaries. These grains are subdivided by high angle boundaries into blocks of martensite laths. The dislocation density of the tempered martensite is high (of about 1014 m-2).

Effect of Tempering Temperature on Mechanical Properties of High Strength Wear Resistant Cast Steel

2013 ◽  
Vol 791-793 ◽  
pp. 440-443
Author(s):  
Hong Bo Li ◽  
Jing Wang ◽  
Han Chi Cheng ◽  
Chun Jie Li ◽  
Xing Jun Su
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Cast Steel ◽  
High Strength ◽  
Fracture Morphology ◽  
Temperature Quenching ◽  
Tempering Temperature ◽  
Wear Resistant ◽  
Dimple Fracture ◽  
The Impact

This paper mainly studied the high temperature quenching oil quenching, tempering temperature on the influence of high strength steel mechanical properties of wear resistant. The results show that high strength and toughness wear-resistant cast steel with 880°C× 30min after oil quenching, the hardness of 38.6HRC steel, the impact toughness value reaches 40.18J/cm2. After 200°C, 400°C and 600°C tempering, with the increase of the tempering temperature, the hardness decreased linearly, as by 600°C tempering, the hardness has been reduced to 22.3HRC. Impact toughness with the tempering temperature, the overall upward trend, the impact toughness of some reduced at 400°C, the highest impact toughness value reaches 113.34J/cm2. From the fracture morphology can be seen, with the increase of tempering temperature, ductile fracture increased, by 600°C tempering is dimple fracture, obviously can not see the traces of brittle fracture.

Phases in Austenitic Cast Steel

2012 ◽  
Vol 326-328 ◽  
pp. 215-220 ◽  
Author(s):  
Małgorzata Garbiak ◽  
Bogdan Piekarski
Keyword(s):  
Annealing Temperature ◽  
Cast Steel ◽  
Intermetallic Phases ◽  
X Ray Diffraction ◽  
Cast State ◽  
Electrolytic Extraction ◽  
X Ray ◽  
Titanium Carbonitrides ◽  
C 30 ◽  
Double Carbides

The paper presents the characteristics of intermetallic phases occurring in heat-resistant cast austenitic 0.3% C-30% Ni-18% Cr steel with additions of niobium and titanium. Five alloys were examined, in which the content of the examined elements was (wt.%) Nb 0.03, 0.55, 1.57 and 1.92, and Ti 0.03, 0.05, 0.30, 0.83 and 1.00. The phase composition of alloys in as-cast state and after annealing (temperature of 800°C and 900°C, time of up to 300 hrs) was examined by X-ray diffraction technique. Depending on the chemical composition of cast steel, carbides of MC type (NbC, TiC, (Nb,Ti)C), M23C6, titanium carbonitrides TiCN and G phase were identified in its microstructure. The phase morphology was examined on the polished sections and surfaces of metallographic specimens after deep etching by electrolytic extraction method. It was found that M23C6carbides assume the shape of rods, NbC carbides crystallise in the form of lamellae, and titanium carbonitrides TiCN in the form of cubes. An addition of both the stabilising elements favours the formation of double carbides (Nb,Ti)C of octahedral habit.

scholarly journals Corrosion Behaviour of Low-Alloyed Cast Steel in Diverse State

2015 ◽  
Vol 15 (1) ◽  
pp. 25-28
Author(s):  
M. Kondracki ◽  
A. Studnicki ◽  
J. Szajnar
Keyword(s):  
Heat Treatment ◽  
Corrosion Test ◽  
High Salinity ◽  
Corrosion Behaviour ◽  
Cast Steel ◽  
Mining Industry ◽  
Cast State ◽  
Alloyed Cast ◽  
Cast Steels ◽  
Parts Manufacturing

Abstract In the paper the results and analysis of corrosion tests were presented for low-alloyed cast steel in as-cast state and after heat treatment operations. Such alloys are applied for heavy loaded parts manufacturing, especially for mining industry. The corrosion test were performed in conditions of high salinity, similar to those occurring during the coal mining. The results have shown, that small changes in chemical composition and the heat treatment influence significantly the corrosion behaviour of studied low-alloyed cast steels.

Mechanical Properties of G17CrMoV5 – 10 Cast Steel after Regenerative Heat Treatment

2009 ◽  
Vol 147-149 ◽  
pp. 732-737 ◽  
Author(s):  
Grzegorz Golański
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Energy ◽  
Cast Steel ◽  
Negative Influence ◽  
Optimum Combination ◽  
Structure And Properties ◽  
Tempering Temperature ◽  
Regenerative Heat ◽  
Bainitic Structure

The paper presents results of research on the influence of regenerative heat treatment on structure and properties of G17CrMoV5 – 10 cast steel. Investigated material was taken out from a turbine frame serviced for over 250 000 hours (total service time) at the temperature of 535 oC. The cast steel after service revealed degraded bainitic-ferritic structure and was characterized by mechanical properties ranging below norm requirements. It has been proved that high tempering temperature in the case of cast steel with bainitic structure ensures optimum combination of mechanical properties and impact energy. It has also been shown that ferrite has a negative influence on impact energy of the cast steel with bainitic-ferritic structure.

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