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.

Microstructure and Mechanical Properties of G17CrMoV5 – 10 Cast Steel After Regenerative Heat Treatment

2009 ◽  
Author(s):  
Grzegorz Golan´ski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Energy ◽  
Cast Steel ◽  
Optimum Combination ◽  
Austenitizing Temperature ◽  
Regenerative Heat ◽  
Term Operation ◽  
Structure Degradation

The paper presents results of research on the influence of regenerative heat treatment on microstructure and properties of a cast steel after long term operation at the elevated temperature. The material under investigation was G17CrMoV5 – 10 cast steel taken out (in the form of a section) from an internal frame of steam turbine serviced for about 250 000 hours. Performed research has proved that, through the structure degradation, long-term service contributes to an increase of brittleness and decrease of mechanical properties — higher in the case of yield strength than tensile strength. The heat treatment, however, contributes to an increase of impact energy, regardless of the applied parameters. Is has also been proved that the optimum combination of mechanical properties and impact energy is ensured by the structure of high tempered bainite. Low mechanical properties and impact energy, however, were obtained for the structure which was slowly cooled from the austenitizing temperature, i.e. the ferritic – bainitic – ferritic structure.

The effect of heat treatment on the mechanical properties of a low carbon steel (0.1%) for offshore structural application

2012 ◽  
Vol 226 (3) ◽  
pp. 242-251 ◽  
Author(s):  
Sung S Kang ◽  
Amir Bolouri ◽  
Chung-Gil Kang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Cooling Rate ◽  
Impact Energy ◽  
Cast Steel ◽  
Low Carbon ◽  
Austenite Grain Size ◽  
Tempering Temperature ◽  
Austenite Grain

In this study, a low carbon cast steel (0.1% C) alloy designed for offshore structures, and the mechanical properties of the alloy under different heat treatment cycles have been evaluated. The effect of austenitizing time on the austenite grain size was studied. Subsequently, the quenched samples with minimum austenite grain size subjected to tempering experiments at different tempering temperatures (450 °C, 550 °C, and 650 °C) and cooling rates (0.23, 36, and 50 °C/s) from the temperature. The results showed that by increasing the austenitizing time, the austenite grain size initially decreased and reached the minimum value with ASTM number of 6.35 and then followed by an increase. When the tempering temperature increased, yield and tensile strengths decreased, whereas the ductility properties improved. In addition, yield and tensile strengths were not affected by cooling rate from tempering temperature, whereas the ductility properties were slightly affected. The increase in tempering temperature significantly led to improvement in the toughness to fracture of the alloy. The effect of cooling rate on impact energy for the samples tempered at 450 °C and 550 °C was negligible. By the contrast, impact energy for the samples tempered at 650 °C was markedly affected by cooling rate, in which the highest value was achieved for a cooling rate of 50 °C/s.

Microstructure and Mechanical Properties of G17CrMoV5-10 Cast Steel After Regenerative Heat Treatment

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Grzegorz Golański
Keyword(s):  
Heat Treatment ◽  
Impact Energy ◽  
Cast Steel ◽  
Strength Properties ◽  
Optimum Combination ◽  
Austenitizing Temperature ◽  
Energy Increase ◽  
Regenerative Heat ◽  
Term Operation

This paper presents the results of a research on the influence of regenerative heat treatment on microstructure and properties of a cast steel after long-term operation at the elevated temperature. The material under investigation was G17CrMoV5-10 cast steel taken out (in the form of a section) from an internal frame of steam turbine serviced for about 250,000 h. Performed research has proven that through the microstructure degradation long-term service contributes to an embrittlement and decrease in yield strength and tensile strength. The heat treatment, however, contributes to an impact energy increase regardless of the applied parameters (cooling rate). It has also been established that the optimum combination of strength properties and impact energy is ensured by the microstructure of high tempered bainite, whereas low strength properties and impact energy were obtained for the microstructure, which was slowly cooled from the austenitizing temperature, i.e., the ferritic-bainitic-ferritic microstructure.

Effect of Different Heat Treatments on Microstructure and Mechanical Properties of the Martensitic Gx12CrMoVNbN9-1 Cast Steel / Wpływ Parametrów Obróbki Cieplnej Na Mikrostrukture I Własciwosci Mechaniczne Martenzytycznego Staliwa Gx12CrMoVNbn9-1

2013 ◽  
Vol 58 (1) ◽  
pp. 25-30 ◽  
Author(s):  
G. Golanski ◽  
J. Słania
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Energy ◽  
Cast Steel ◽  
Lath Martensite ◽  
High Strength ◽  
Strength Properties ◽  
Microstructure And Mechanical Properties ◽  
Quenching And Tempering ◽  
Very High

The paper presents a research on the influence of multistage heat treatment with the assumed parameters of temperature and time on the microstructure and mechanical properties of high-chromium martensitic GX12CrMoVNbN9-1 (GP91) cast steel. In the as-cast state GP91 cast steel was characterized by a microstructure of lath martensite with numerous precipitations of carbides of the M23C6, M3C and NbC type, with its properties higher than the required minimum. Hardening of the examined cast steel contributes to obtaining a microstructure of partly auto-tempered martensite of very high strength properties and impact strength KV on the level of 9-15 J. Quenching and tempering with subsequent stress relief annealing of GP91 cast steel contributed to obtaining the microstructure of high-tempered lath martensite with numerous precipitations of the M23C6 and MX type of diverse size. The microstructure of GP91 cast steel received after heat treatment was characterized by strength properties (yield strength, tensile strength) higher than the required minimum and a very high impact energy KV. It has been proved that GP91 cast steel subject to heat treatment No. 2 as a result of two-time heating above the Ac3 temperature is characterized by the highest impact energy.

The effect of heat treatment on mechanical properties of 42CrMo4 steel

2020 ◽  
Vol 1 (98) ◽  
pp. 5-10
Author(s):  
A. Çalık ◽  
O. Dokuzlar ◽  
N. Uçar
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Stress ◽  
Yield Stress ◽  
Impact Energy ◽  
Ultimate Tensile Stress ◽  
Tempering Temperature ◽  
Heat Treated ◽  
Quenching Process ◽  
42Crmo4 Steel

Purpose: In this study, the effect of heat treatment on the microstructure and mechanical properties of 42CrMo4 steel were investigated. Design/methodology/approach: The samples were annealed at 860°C for 120 min. followed by oil quenching and then tempered at temperatures between 480 and 570°C for 120 min. The microstructure of untreated 42CrMo4 steel mainly consists of pearlite and ferrite whereas the microstructure was found to be as a martensitic structure with a quenching process. Findings: The results showed that there is an increase in yield stress, ultimate tensile stress, hardness and impact energy, while elongation decreases at the end of the quenching process. Conversely, yield stress, ultimate tensile stress and hardness decrease slightly with the increasing of tempering temperature, while elongation and impact energy increase. Research limitations/implications: Other types of steels can be heat treated in a wider temperature range and the results can be compared. Practical implications: It is a highly effective method for improving the mechanical properties of heat treatment materials. Originality/value: A relationship between the mechanical properties and the microstructure of materials can be developed. The heat treatment is an effective method for this process.

scholarly journals Effect of Tempering Temperature on the Mechanical Properties of Cast L35HM Steel

2017 ◽  
Vol 17 (2) ◽  
pp. 151-156
Author(s):  
R. Zapała ◽  
B. Kalandyk ◽  
P. Wawro
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aqueous Solution ◽  
Cast Steel ◽  
Tempering Temperature ◽  
The Difference

Abstract A possibility to control the strength, hardness and ductility of the L35HM low-alloy structural cast steel by the applied tempering temperature is discussed in the paper. Tests were carried out on samples taken from the two randomly selected industrial melts. Heat treatment of the cast samples included quenching at 900 °C, cooling in an aqueous solution of polymer, and tempering at 600 and 650 °C. The obtained results showed that the difference in the tempering temperature equal to 50 °C can cause the difference of 121 MPa in the values of UTS and of 153 MPa in the values of 0.2%YS. For both melts tempered at 600 °C, the average values of UTS and 0.2%YS were equal to 995 MPa and 933 MPa, respectively. The values of EL and RA did not show any significant differences. Attention was drawn to large differences in strength and hardness observed between the melts tempered at 600 and 650 °C. Despite differences in the mechanical properties of the examined cast steel, the obtained results were superior to those specified by the standard.

Effect of Tempering Process on Microstructure and Mechanical Properties of Low Alloyed Cast Steel

2021 ◽  
Vol 871 ◽  
pp. 40-45
Author(s):  
Hui Ji Fan ◽  
Bo Chen ◽  
Jun Wen ◽  
Xin Jin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Energy ◽  
Cast Steel ◽  
Granular Bainite ◽  
Tempering Temperature ◽  
Microstructure And Properties ◽  
Alloyed Cast ◽  
Microstructure And Mechanical Properties ◽  
Tempering Process

The effect of tempering process on the microstructure and properties of low alloyed cast steel was studied. The results show that tempered at (200~400)°C, the M/A island of the granular bainite decomposes and carbide precipitates. When the tempering temperature rises to (500~600)°C, the M/A island is completely decomposed, and the carbide aggregates and gradually spheroidizes. With the increasing of tempering temperature, the tensile strength increases first and then decreases, elongation and impact energy show a trend of increasing at first, then decreasing and then increasing. The tempering brittleness occurs at 400°C.

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.

Influence of Heat Treatment on Mechanical Properties and Microstructure of Low Alloy Cast Steel (ZG25MnNi)

2014 ◽  
Vol 887-888 ◽  
pp. 207-213
Author(s):  
Teng Shi Liu ◽  
Yi Tao Yang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Cast Steel ◽  
High Strength ◽  
Treatment Temperature ◽  
Maximum Hardness ◽  
Tempering Temperature ◽  
Cast Microstructure ◽  
Alloy Cast

In this paper, the influence of heat treatment temperature on the microstructure and mechanical properties of cast steel (ZG25MnNi) was investigated. The results showed that normalizing treatment can effectively refine cast microstructure of ZG25MnNi and maximum hardness achieved at 900°C. After normalized at 900°C, the sample tempered at 500°C,530°C,560°C, 590°C, 620°C, 650°C respectively. With the tempering temperature increasing, the samples tensile strength increased gradually and elongation decreased gradually. When tempered at 530-590°C, the sample had a relatively high strength plastic product. The results showed that the best normalizing temperature is 900°C and the optimum tempering temperature is 530-590°C.

scholarly journals Investigation of the effect of isothermal heat treatments on mechanical properties of thermo-mechanically rolled S700MC steel grade

2020 ◽  
Vol 26 (1) ◽  
pp. 11-16
Author(s):  
Serkan Oktay ◽  
Paolo Emilio Di Nunzio ◽  
Mustafa Kelami Şeşen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Energy ◽  
Heat Treatments ◽  
Steel Grade ◽  
Secondary Hardening ◽  
Precipitation Kinetics ◽  
High Supersaturation ◽  
Bainitic Structure ◽  
Isothermal Heat Treatments

The effect of isothermal heat treatments (1 hour at 200, 400, 600 and 800°C) on mechanical properties of thermo-mechanically rolled S700MC steel has been investigated by extensive mechanical characterizations. Treatments at 600°C increase yield and tensile strength and decrease impact energy. Below 600°C the steel retains its bainitic structure. Precipitation kinetics simulations indicate that this secondary hardening effect arises from the nucleation of fine (Nb,Ti)C particles, indicating that the bainitic structure is unstable above 600°C due to its high supersaturation with respect to C, Nb and Ti. These results can help to optimize the operating practices for post-weld heat treatments.

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