Influence of heat treatment on the impact strength of 40Kn steel

1984 ◽  
Vol 16 (4) ◽  
pp. 496-499
Author(s):  
V. K. Golubev ◽  
S. A. Novikov ◽  
Yu. S. Sobolev ◽  
H. A. Yukina
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
The Impact

scholarly journals Effect of Soft Annealing Treatment on Impact Strength and Hardness of the EN AC-AlSi11 Alloy

2017 ◽  
Vol 17 (3) ◽  
pp. 55-58
Author(s):  
A. Jarco
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Direct Effect ◽  
Brinell Hardness ◽  
Eutectic Silicon ◽  
Annealing Treatment ◽  
Input Parameters ◽  
The Impact ◽  
Testing Plan

Abstract The paper presents research on the effects of soft annealing parameters on a change of the impact strength KC and Brinell hardness (HB) of the EN AC-AlSi11 alloy. The research has been performed according to the trivalent testing plan for two input parameters – temperature in the range between 280°C and 370°C and time in the range between 2 and 8 hours. The application of such heat treatment improves the plasticity of the investigated alloy. The improvement of the impact strength KC by 71% and the decrease of the hardness HB by 20% was achieved for the soft annealing treatment conducted at a temperature 370°C for 8 hours, compared to the alloy without the heat treatment. A change of the form of eutectic silicon precipitations which underwent refinement, coagulation and partial rounding, had a direct effect on the hardness HB and impact strength KC. The results obtained were used to prepare space plots enabling the temperature and time for soft annealing treatment to be selected with reference to the obtained impact strength KC and hardness HB of the alloy with the heat treatment.

The Influence of Boron on Structure and Mechanical Properties of Bainite Ductile Iron in the Step Austempering in Room Temperature Machine Oil

2010 ◽  
Vol 139-141 ◽  
pp. 235-238
Author(s):  
De Qiang Wei
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Iron ◽  
Impact Strength ◽  
Ductile Iron ◽  
Room Temperature ◽  
Solute Drag ◽  
Ductile Cast Iron ◽  
Treatment Technique ◽  
The Impact

In this paper, the low alloy bainite ductile cast iron has been obtained by a new heat treatment technique of the step austempering in room-temperature machine oil. The effects of element boron, manganese and copper on structure and mechanical properties of the bainite ductile cast Iron in above-mentioned process are investigated. The phenomenon, hardness lag of the alloyed bainite ductile cast Iron, has been discussed. It shows that after the step austempering in room-temperature machine oil, the hardness will increases with the time. It is found that boron and manganese can increase the hardness and reduce the impact strength while copper can increase the impact strength. The results show that reasonable alloyed elements can improve mechanical properties of the bainite ductile cast Iron. Essentially, hardness lag of the alloyed bainite ductile cast Iron is resulted from solute drag-like effect.

The Causes of Low Impact Strength of T23 Steel Weld Joints

2015 ◽  
Vol 226 ◽  
pp. 103-106
Author(s):  
Janusz Adamiec ◽  
Izabela Pikos ◽  
Michał Stopyra
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Weld Metal ◽  
Post Weld Heat Treatment ◽  
Weld Joints ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
The Impact ◽  
Welding Technique ◽  
Weld Heat

T23 is modern bainitic steel designed for use in supercritical boilers. According to producer’s data weldability of this steel is good enough to avoid post-weld heat treatment. However, some of the T23 weld joints in as-welded condition have not met the minimal ductility requirement. The impact test revealed significant differences between the joints in as-welded and heat treated condition. Metallographic and fractographic examinations have been conducted in order to explain those differences. The specimens with low impact strength were characterized by brittle fracture and non-tempered martensite presence in weld metal. It was concluded that avoiding formation of disadvantageous structure in weld metal requires conducting of post weld heat treatment or applying multi-pass welding technique with annealing run.

scholarly journals Effect of the Annealing Temperature on the Microstructure and Properties of Ausferritic Nodular Cast Iron

2016 ◽  
Vol 16 (3) ◽  
pp. 43-48 ◽  
Author(s):  
G. Gumienny ◽  
L. Klimek ◽  
B. Kurowska
Keyword(s):  
Heat Treatment ◽  
Cast Iron ◽  
Impact Strength ◽  
Lamellar Structure ◽  
Annealing Temperature ◽  
Nodular Cast Iron ◽  
Iron Matrix ◽  
Secondary Carbides ◽  
Nodular Graphite ◽  
The Impact

Abstract The paper presents the microstructure and selected properties of ausferritic nodular cast iron annealed at the temperature 520 and 550°C. This choice was dictated by the temperatures used in the practice of nitriding. Nodular graphite in cast iron was obtained with use of Inmold process. Cast iron containing molybdenum and copper ensuring obtaining an ausferrite in the cast iron matrix without the use of heat treatment of castings was tested. The effect of annealing temperature on the microstructure and the kind of fracture of the ausferritic nodular cast iron was presented. The effect of an annealing temperature on hardness, impact strength and the microhardness of ausferritic nodular cast iron matrix was shown too. The lamellar structure of phases in the cast iron matrix after annealing has been ascertained. There has been an increase in hardness of an annealed cast iron and microhardness of its matrix. The reduction in the impact strength of the cast iron annealed at 520 and 550°C was approximately 10-30%. Both an increase in the hardness of cast iron as well as an decrease in its impact strength is probably due to the separation of secondary carbides during the heat treatment.

scholarly journals Effect of dopant and heat treatment on the microstructure and mechanical properties of Nickel-Aluminum bronze.

10.30544/423 ◽  
2019 ◽  
Vol 25 (2) ◽  
pp. 147-162
Author(s):  
Franklin Amaechi Anene ◽  
Nkem Emelike Nwankwo ◽  
Victor Ugochukwu Nwoke
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Impact Strength ◽  
Aluminum Bronze ◽  
Nickel Aluminum ◽  
Β Phase ◽  
Microstructure And Mechanical Properties ◽  
Nickel Aluminum Bronze ◽  
The Impact

The effect of dopant and heat treatment on the microstructure and mechanical properties of Nickel-aluminum bronze (Cu-10%Al-5%Ni-5%Fe-x%Mo) were extensively investigated. The cast samples were heat treated through different processes, including solutionizing, quenching, and aging; their microstructures were examined using an optical microscope, scanning electron microscopy and energy dispersive spectroscopy analysis and their mechanical properties determined. The microstructure of the as-cast samples consisted of Cu-rich ‘α-phase, ‘κ-phases and small volume fraction of β'-phase while solutionizing transformed the β'-phase to a homogenous β-phase, α, and κ phases. Quenching transformed all β phase to β'-phase, however, aging the alloy precipitated fine dispersive strengthening κ-phases from the quenched microstructure. The results of the mechanical tests showed that the aged samples had improved excellent mechanical properties compared to the as-cast samples. Compared to the base alloy, the tensile strength and hardness of the aged 2% Mo sample increased by 58% and 55%, respectively while the impact strength and elongation decreased by 27% and 22%, respectively. Similarly, the tensile strength and hardness of the aged 3% Mo sample increased by 44% and 49%, respectively, while the impact strength and % elongation decreased by 23.9% and 24.9%, respectively.

scholarly journals Influence of Heat Treatment Technologies on the Structure and Properties of the Corrosion-Resistant Martensitic Steel Type AISI 420

2020 ◽  
Vol 7 (2) ◽  
pp. C10-C16
Author(s):  
O. Lupyr ◽  
T. Hovorun ◽  
S. Vorobiov ◽  
А. Burlaka ◽  
R. Khvostenko
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Tap Water ◽  
Turbine Blades ◽  
Atmospheric Precipitation ◽  
Air Cooling ◽  
Tempering Temperature ◽  
Aisi 420 ◽  
Martensitic Class ◽  
The Impact

One of the methods for increasing the complexity of chromium steel properties of martensitic class AISI 420 is the use of an optimal heat treatment mode. The steel of martensitic class AISI 420 has high resistance in atmospheric conditions (except for the sea atmosphere), in the river, and tap water. It is widely used in power engineering, in cracking units with a long service life at temperatures up to 500 °C, for furnace parts. Additionally, it is used in the following fields: the production of turbine blades, working in conditions of high temperatures and parts of increased plasticity, subject to shock loads, for products exposed to atmospheric precipitation, solutions of organic salts and other slightly aggressive environments; production of fasteners; production of parts for compressor machines operating with inert gas; production of parts operating at low temperatures in corrosive environments; production of parts for aviation purposes. It is shown that the optimal mode of heat treatment for a maximum hardness of 40 HRC is quenching at a temperature of 980 °C with cooling in oil and tempering at a temperature of 200 °C with air cooling. With an increase in the tempering temperature from 200 °C to 450–500°C, the impact strength does not change much. Tempering at higher temperatures leads to the intense weakening of the steel. Simultaneously, a decrease in the impact strength is observed, the minimum value is reached at a tempering temperature of 550 °C. With an increase in the tempering temperature to 700 °C, the impact toughness increases, but the steel’s hardness sharply decreases at such temperatures. Keywords: hardening, tempering, hardness, toughness, mechanical properties, chromium carbide.

scholarly journals Effect of Different Variants of Heat Treatment on Mechanical Properties of the AlSi17CuNiMg Alloy

2016 ◽  
Vol 16 (2) ◽  
pp. 41-44 ◽  
Author(s):  
A. Jarco ◽  
J. Pezda
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Impact Strength ◽  
High Hardness ◽  
Dispersion Hardening ◽  
Initial State ◽  
Plastic Properties ◽  
Fourfold Increase ◽  
The Impact

Abstract Dispersion hardening, as the main heat treatment of silumins having additions of copper and magnesium, results in considerable increase of tensile strength and hardness, with simultaneous decrease of ductility of the alloy. In the paper is presented an attempt of introduction of heat treatment operation consisting in homogenizing treatment prior operation of the dispersion hardening, to minimize negative effects of the T6 heat treatment on plastic properties of hypereutectoidal AlSi17CuNiMg alloy. Tests of the mechanical properties were performed on a test pieces poured in standardized metal moulds. Parameters of different variants of the heat treatment, i.e. temperature and time of soaking for individual operations were selected basing on the ATD (Thermal Derivation Analysis) diagram and analysis of literature. The homogenizing treatment significantly improves ductility of the alloy, resulting in a threefold increase of the elongation and more than fourfold increase of the impact strength in comparison with initial state of the alloy. Moreover, the hardness and the tensile strength (Rm) of the alloy decrease considerably. On the other hand, combination of the homogenizing and dispersion hardening enables increase of elongation with about 40%, and increase of the impact strength with about 25%, comparing with these values after the T6 treatment, maintaining high hardness and slight increase of the tensile strength, comparing with the alloy after the dispersion hardening.

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