Bainitic hardening of iron from cast state

2007 ◽  
Vol 49 (7-8) ◽  
pp. 401-404
Author(s):  
K. V. Makarenko
Keyword(s):  
Cast State ◽  
Bainitic Hardening

scholarly journals Joining of SiO2 glass and 316L stainless steel using Bi–Ag-based active solders

2020 ◽  
Vol 56 (4) ◽  
pp. 3444-3454
Author(s):  
Felix Weber ◽  
Markus Rettenmayr
Keyword(s):  
Stainless Steel ◽  
Cross Sections ◽  
316L Stainless Steel ◽  
Dissimilar Materials ◽  
Intermetallic Phases ◽  
Reaction Products ◽  
Cast State ◽  
Metallic Component ◽  
X Ray ◽  
Solder Interface

Abstract Active brazing is a commonly used method for joining dissimilar materials with at least one non-metallic component. In the present study, joining of SiO2 glass to 316L stainless steel was performed utilizing Bi–Ag-based solders. Ti up to a concentration of 4 and Mg up to 1 wt.% were added as active elements. Microstructures of the solder alloys in the as-cast state and of cross sections of the joined compounds were analysed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. In the as-cast state of the solder, Ti is found in Bi–Ti intermetallic phases; Mg is partially dissolved in the fcc-(Ag) phase and additionally contained in a ternary Ag-Bi-Mg phase. After soldering, a tight joint was generated using several alloy compositions. Ti leads to the formation of reaction products at the steel/solder and glass/solder interfaces, and Mg is exclusively accumulated at the glass/solder interface.

Microstructural Changes of Welded Zn-AI Alloy

1994 ◽  
Vol 367 ◽  
Author(s):  
Yao Hua Zhu
Keyword(s):  
Phase Transformation ◽  
Early Stage ◽  
Dendritic Structure ◽  
Metastable Phases ◽  
Grain Structure ◽  
Al Alloy ◽  
Cast State ◽  
Microstructural Changes ◽  
Fine Grain ◽  
Ageing Processes

AbstractExtruded eutectoid Zn-Al alloy was welded by a melt of the same eutectoid alloy. Two different microstructures were observed in the joint part and the bulk of the welded alloy. Typical dendritic structure of as cast Zn-Al alloy was observed in the joint part of the welded alloy. The bulk ofthe welded Zn-Al alloy appeared as fine grain structure. Two different metastable phases η'T decomposed from η's of chilled as cast state and η'E of extruded state were found to be unstable during early stage of ageing. A four phase transformation occurred after the decompositions of these two metastable phases of η'T. Microstructures of both joint part and bulk of the welded alloy were investigated parallely during ageing processes.

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 Structure and properties of an Al alloy in as-cast state and after laser treatment

2016 ◽  
Vol 65 (2) ◽  
pp. 107 ◽  
Author(s):  
M Król ◽  
P Snopiński ◽  
B Tomiczek ◽  
T Tański ◽  
W Pakieła ◽  
...  
Keyword(s):  
Laser Treatment ◽  
Al Alloy ◽  
Structure And Properties ◽  
Cast State

scholarly journals A Conflict of Fineness and Stability: Platinum- and Palladium-Based Bulk Metallic Glasses for Jewellery

2020 ◽  
Author(s):  
O. S. Houghton ◽  
A. L. Greer
Keyword(s):  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
Precious Metals ◽  
High Hardness ◽  
Scratch Resistance ◽  
Cast State ◽  
High Definition ◽  
Glass Forming ◽  
Thermoplastic Forming ◽  
Near Net Shape

For the metals used in jewellery, high hardness and the associated scratch resistance are much sought after. Conventional crystalline alloys for jewellery are alloyed and extensively processed (thermally and mechanically) to improve hardness, but it is difficult to reach values beyond 300 HV. The advent of bulk metallic glasses, based on precious metals and with hardness exceeding 300 HV in the as-cast state, is therefore of great interest for both jewellery and watchmaking. The non-crystalline structure of these materials not only gives high hardness, but also the opportunity to shape metals like plastics, via thermoplastic forming. For more traditional jewellery manufacture, bulk metallic glasses also exhibit high-definition and near-net-shape casting. Gold-based alloys have long dominated the consideration of bulk metallic glasses for jewellery as they can comply with 18K hallmarks. Although bulk metallic glasses based on platinum or palladium possess excellent thermoplastic formability, and are without known tarnishing problems, achieving useful glass-forming ability within the more restrictive hallmarking standards typically used for jewellery (≥95 wt.% Pt or Pd) is, at best, challenging. In this review, platinum- and palladium-based bulk metallic glasses are discussed, focusing on their potential application in jewellery and on the further research that is necessary.

scholarly journals Increased stability die forged steel 4H4N5M4

2020 ◽  
Vol 96 (4) ◽  
pp. 30-38
Author(s):  
O. M. Sydorchuk ◽  
◽  
L. A. Myroniuk ◽  
D. V. Myroniuk ◽  
K. O. Gogaev ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Physical And Mechanical Properties ◽  
Cast State ◽  
H13 Steel ◽  
Die Steel ◽  
Lower Heat ◽  
Full Annealing ◽  
Processing Optimization ◽  
Inner Parts ◽  
Steel Heat

The results of researches on steel 4H4N5M4F2 modes thermo-deformation processing optimization are given. It is established that incomplete annealing (750 °С ± 20 °С in comparison with full annealing 860 °С) in cast and forged condition promotes to improve the machining of blanks for the manufacture of matrices. It is shown that the use of incomplete annealing, namely partial recrystallization promotes the formation of spheroidized rather than lamellar carbide phase, which leads to a decrease in the characteristics: strength threshold, yield strength, hardness 900 MPa, 800 MPa, 32 33 HRC in the cast state and 1200 MPa, 1050 MPa, 38 39 HRC in forged condition, respectively. This increases the fracture toughness: 180 J/cm2 in the cast state and 130 J/cm2 in the forged state. The optimized mode of forging at the temperature of 1170 ± 20 °С and heat treatment (hardening at 1100 ± 5 °С and tempering at 595 ± 5 °С) of steel 4H4N5M4F2 allowed to increase impact strength five times in comparison with cast experimental steel, and also to increase strength threshold of 100 MPa. Forged steel 4H4N5M4F2 has slightly lower heat resistance compared to cast, which hardens at temperatures above 630 °C during operation of the die steel tool. After operation of the extruder wheels made of investigated forged steel and forged steel 4H5MF1S, which was used at the enterprise in copper processing, the properties of both steels were determined. The investigated forged steel 4H4N5M4F2 is characterized by an increase in the strength threshold by 200 MPa and hardness by 6 HRC. After operation (production of 60 tons of copper products of M1 grade) the tool (wheel extruder) from H13 steel (analog 4H5MF1S) had micro and macrocracks on the side and inner parts, and in the investigated steel 4H4N5M4F2 such defects were absent. Thus, the studied steel is characterized by increased stability. Keywords: steel, heat treatment, forging, structure, physical and mechanical properties.

scholarly journals The Dilatometric Analysis of the High Carbon Alloys from Ni-Ta-Al-M System

2014 ◽  
Vol 59 (3) ◽  
pp. 977-980 ◽  
Author(s):  
P. Bała
Keyword(s):  
Elevated Temperatures ◽  
Volume Fraction ◽  
Intermetallic Phase ◽  
Coarse Grained ◽  
Precipitation Process ◽  
Cast State ◽  
High Carbon ◽  
Chromium Carbides ◽  
Tantalum Carbides ◽  
Co Alloys

Abstract In the following work presents results of high carbon alloys from the Ni-Ta-Al-M system are presented. The alloys have been designed to have a good tribological properties at elevated temperatures. Despite availability of numerous hot work tool materials there is still a growing need for new alloys showing unique properties, which could be used under heavy duty conditions, i.e. at high temperatures, in a chemically aggressive environment and under heavy wear conditions. A characteristic, coarse-grained dendritic microstructure occurs in the investigated alloys in the as-cast condition. Primary dendrites with secondary branches can be observed. Tantalum carbides of MC type and graphite precipitations are distributed in interdendritic spaces in the Ni-Ta-Al-C and Ni-Ta-Al-C-Co alloys, while Tantalum carbides of MC type and Chromium carbides of M7C3 type appeared in the Ni-Ta-Al-C-Co-Cr and Ni-Ta-Al-C-Cr alloys. In all alloys g’ phase is present, however, its volume fraction in the Ni-Ta-Al-C and Ni-Ta-Al-C-Co alloys is small.During heating from as-cast state in Ni-Ta-Al-C and Ni-Ta-Al-C-Co alloys, the beginning of the tantalum carbides precipitation process (MC type) followed (or simultaneous) by the intermetallic phase precipitation (g’ – Ni3(AlTa)) was stated, while in Ni-Ta-Al-C-Co-Cr and Ni-Ta-Al-C-Cr alloys, besides Tantalum carbides also the Chromium carbides precipitation occurred. It means that the investigated alloys were partially supersaturated in as-cast state. Above 1050°C in all investigated alloys the g’ phase is dissolving. In addition, the precipitation of secondary carbides during slow cooling was occured.

scholarly journals Impact of a Structure on Durability of Modified Nickel-Base Superalloys in Creep Conditions/ Wpływ Struktury Na Trwałość W Warunkach Pełzania Modyfikowanych Nadstopów Na Bazie Niklu

2014 ◽  
Vol 59 (4) ◽  
pp. 1559-1563 ◽  
Author(s):  
M. Ciesla ◽  
M. Manka ◽  
P. Gradon ◽  
F. Binczyk
Keyword(s):  
Creep Resistance ◽  
Morphological Structure ◽  
Aircraft Engine ◽  
Coarse Grained ◽  
Test Results ◽  
Cast State ◽  
Accelerated Creep ◽  
Nickel Base ◽  
The Impact ◽  
Modification Treatment

Abstract The study assesses the impact of surface and bulk modification and filtration during pouring on a durability under accelerated creep conditions of casts made of IN-713C and MAR-247 nickel superalloys scrap used for manufacturing of aircraft engine parts. The impact of solutionizing (1185°C/2 h) with subsequent ageing (870°C/20 h) on the creep resistance of a casting made from MAR-247 coarse-grained superalloy was also examined. Morphological structure parameters were determined with the use of Met-Ilo software. Macrostructure analysis of casts showed very significant impact of surface modification treatment. Creep test results clearly showed that coarse grained samples of IN-713C and MAR-247 superalloys have higher creep resistance. Moreover alloy MAR-247 had higher creep durability after heat treatment compared to as-cast state.

Microstructure and Mechanical Performance of AZ31-1.7 Wt.% Si Alloy Processed by Cyclic Channel Die Compression

2010 ◽  
Vol 667-669 ◽  
pp. 457-461
Author(s):  
Wei Guo ◽  
Qu Dong Wang ◽  
Man Ping Liu ◽  
Tao Peng ◽  
Xin Tao Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Mechanical Performance ◽  
Chinese Script ◽  
Cast State ◽  
Microstructure And Mechanical Properties ◽  
Mean Grain Size ◽  
The Matrix ◽  
The Mean

Cyclic channel die compression (CCDC) of AZ31-1.7 wt.% Si alloy was performed up to 5 passes at 623 K in order to investigate the microstructure and mechanical properties of compressed alloys. The results show that multi-pass CCDC is very effective to refine the matrix grain and Mg2Si phases. After the alloy is processed for 5 passes, the mean grain size decreases from 300 μm of as-cast to 8 μm. Both dendritic and Chinese script type Mg2Si phases break into small polygonal pieces and distribute uniformly in the matrix. The tensile strength increases prominently from 118 MPa to 216 MPa, whereas the hardness of alloy deformed 5 passes only increase by 8.4% compared with as-cast state.

scholarly journals Investigations of Ferritic Nodular Cast Iron Containing About 5-6% Aluminium

2016 ◽  
Vol 16 (4) ◽  
pp. 141-146 ◽  
Author(s):  
M.S. Soiński ◽  
P. Kordas ◽  
K. Skurka ◽  
A. Jakubus
Keyword(s):  
Cast Iron ◽  
Nodular Cast Iron ◽  
Cast State ◽  
Ferritic Matrix ◽  
Laboratory Conditions

Abstract The work presents results of investigations concerning the production of cast iron containing about 5-6% aluminium, with the ferritic matrix in the as-cast state and nodular or vermicular graphite precipitates. The examined cast iron came from six melts produced under the laboratory conditions. It contained aluminium in the amount of 5.15% to 6.02% (carbon in the amount of 2.41% to 2.87%, silicon in the amount of 4.50% to 5.30%, and manganese in the amount of 0.12% to 0.14%). After its treatment with cerium mixture and graphitization with ferrosilicon (75% Si), only nodular and vermicular graphite precipitates were achieved in the examined cast iron. Moreover, it is possible to achieve the alloy of pure ferritic matrix, even after the spheroidizing treatment, when both the aluminium and the silicon occur in cast iron in amounts of about 5.2÷5.3%.

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