scholarly journals Дослідження нагріву високолегованих сталей у нагрівальному колодязі з опаленням з центру поду

2018 ◽  
pp. 81-85
Author(s):  
O.I. Cheprasov ◽  
Yu. M. Kayukov ◽  
I.A. Nazarenko
Keyword(s):  
Initial Temperature ◽  
Temperature Drop ◽  
Exposure Period ◽  
Final Temperature ◽  
High Alloy ◽  
High Alloy Steel ◽  
Temperature State ◽  
Alloy Steels ◽  
Steel Grades ◽  
Steel Ingots

Purpose. Taking into account the steel grade, the mass of the set and the initial temperature state of the metal, it is necessary to estimate the final temperature drop in the steel ingots, which are heated in a recuperative heating well with heating from the hearth. Metodology. The study was performed in the process of heating high-alloy steels in a recuperative heating well by measuring the temperature in an experimental ingot. Findings. The results of thermometry of an experienced ingot with its nod as part of the high-alloy steel set are presented. The final temperature drop in the ingot and the nature of its change in the process of holding the metal have been established. Originality. It was established that the final temperature drop in the experimental ingot is determined by the unevenness of the temperature field of the heating well and is (80 ... 120) ° C. Practical value. Using research results allows us to develop heating modes for stainless steel grades with a shorter (10 ... 20)% exposure period.

scholarly journals Development of Universal Mould Geometry for the Teeming of Cylindrical Iron-Base Alloy Ingots

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 471
Author(s):  
Josef Odehnal ◽  
Pavel Ludvík ◽  
Tomáš Studecký ◽  
Pavel Michálek
Keyword(s):  
Alloy Steel ◽  
Base Alloy ◽  
Cast Steel ◽  
Solidification Process ◽  
High Alloy ◽  
High Alloy Steel ◽  
Iron Base Alloy ◽  
Steel Grades ◽  
Borated Stainless Steel ◽  
Filling And Solidification

The presented work is aimed at developing a mould geometry suitable for casting both low- and high-alloy steel grades into 500 kg experimental ingots. The high Height-to-Diameter (H/D)-ratio mould currently used in COMTES FHT Inc. served as a reference and for finite element method simulations (FEM) of the filling and solidification process. The optimized mould geometry, balancing the porosity and segregations, was determined using MAGMA software. Four different steel grades were defined for the simulation. Case studies were carried out for 34CrNiMo6 (W.Nr. 1.6582), DHQ8, CB2 and borated stainless steel grades ranging from low-alloy steel to high-alloy steel. Extended user-defined criteria and verified boundary conditions were used to predict the formation of A-segregations in cast steel. Both primary (PDAS) and secondary (SDAS) arm spacings were modelled as well. The optimized mould shape and the casting assembly were designed based on the simulation results.

scholarly journals Tool surface with a supporting plateau of hard particles for deep drawing of high alloy steel

2018 ◽  
Vol 190 ◽  
pp. 14006 ◽  
Author(s):  
Hannes Freiße ◽  
Thomas Seefeld
Keyword(s):  
Sheet Metal Forming ◽  
Deep Drawing ◽  
Metal Forming ◽  
Adhesive Wear ◽  
High Alloy ◽  
High Alloy Steel ◽  
Hard Particles ◽  
Aluminium Bronze ◽  
Tool Surface ◽  
Alloy Steels

Sheet metal forming normally requires the application of lubricants to protect the tool and the sheet against wear. The parts must be cleaned to remove the lubricants before joining and coating. This process step wastes energy and water resources. In the case of non-lubricated sheet metal forming, cleaning processes would not be necessary anymore and the process chain could be optimized regarding ecological and economical aspects. However, forming without lubrication leads to an intensive contact between the tool and the sheet. Thus, higher wear occurs and process reliability cannot be ensured for industrial mass production. High alloy steels are applied for mass-market products e.g. for appliances. Because of the higher strength, strain hardening and galling effects the austenitic steels are comparatively difficult to form. For dry metal forming of high alloy steels new tool concept must be developed to withstand the higher loads. In this work, a laser generated tool surface with a supporting plateau of hard particles (metal matrix composite (MMC-surface)) is presented. Spherical fused tungsten carbides were injected into the surface by laser melt injection. The metallic matrix of the composite was rejected by applying laser ablation. In consequence, the hard particles stood out of the matrix and were in direct contact with the sheet material. The surface of hard particles had a high hardness about 3000 HV and less metallic character. Cold working steel and aluminium bronze were tested as reference tool materials. Dry and lubricated forming experiments were carried out by strip drawing with bending and deep drawing of cups. Dry deep drawing of cups was not possible by using cold work tool steel. This can be traced back to the occurrence of wrinkles and cup base fracture at the same time. Applying aluminium bronze as tool material for dry metal forming resulted in high adhesive wear. Within this work the feasibility of dry metal forming of high alloy steel could be demonstrated by applying the MMC-surface whereby adhesive wear could be reduced.

Advancement in Understanding of Descalability during High Pressure Descaling

2014 ◽  
Vol 622-623 ◽  
pp. 29-36
Author(s):  
D. Farrugia ◽  
Andrew Richardson ◽  
Yong Jun Lan
Keyword(s):  
High Pressure ◽  
High Alloy ◽  
Alternative Technologies ◽  
Good Surface ◽  
Recent Developments ◽  
Alloy Steels ◽  
Steel Grades ◽  
Pressure Water ◽  
Jet Nozzle ◽  
Process Factors

This paper building upon studies [1‐8] describes a subset of the High Pressure Water (HPW) descaling strategy developed at Tata Steel UK to optimise descaling set-ups for range of steel grades prone to adherent primary scale such as in high alloy steels (Si, Ni, Cr). Effective primary descaling, i.e. descaling post furnace discharge via washbox or alternative technologies is imperative to obtain good surface quality and conditioning of the surface state as well as the morphology, growth and behaviour of the secondary/tertiary scale. This paper primarily focuses on analytical descaling concepts for both mechanical and thermal outputs for flat jet nozzle and process factors. This approach has been linked to recent developments for oxide scale evolution during rolling and descaling [8].

Forging of High-Alloy Steel Ingots

2018 ◽  
Vol 48 (10) ◽  
pp. 659-662
Author(s):  
V. A. Tyurin ◽  
A. L. Sapunov ◽  
A. A. Chuchkov
Keyword(s):  
Alloy Steel ◽  
High Alloy ◽  
High Alloy Steel ◽  
Steel Ingots

scholarly journals Decarburization of ferrochrome and high alloy steels with optimized gas and slag phases towards improved Cr retention

2013 ◽  
Vol 49 (2) ◽  
pp. 175-181 ◽  
Author(s):  
H. Wang ◽  
M.M. Nzotta ◽  
L. Teng ◽  
S. Seetharaman
Keyword(s):  
Mass Transfer ◽  
Induction Furnace ◽  
Refining Process ◽  
Endothermic Reaction ◽  
High Carbon ◽  
High Alloy ◽  
High Alloy Steel ◽  
Carbon Ferrochrome ◽  
Alloy Steels ◽  
Gas Molecules

Chromium is a high value metal and the retention of the same during the refining of high carbon ferrochrome as well as high alloy steel has significant economic and environmental impacts. The loss of chromium during the decarburization is generally minimized using argon-oxygen mixtures thereby reducing the oxygen partial pressure (PO2) of the oxidant gas. In the current study, experiments were carried out in an induction furnace and CO2 was introduced with the view to partly reduce PO2 and partly as an oxidizer. During these experiments, the decarburization of molten Cr-alloy was conducted using pure O2, pure CO2 or O2+CO2 mixtures. The results demonstrated that the Cr loss can be minimized under CO2 introduction. The kinetic analysis showed that the mass transfer is effective due to the production of 2CO gas molecules from one CO2 molecule during the reaction which will improve the stirring of the bath. Besides, CO2 reacts with carbon in melt is an endothermic reaction, introduction of CO2 could be a cooler during the refining process, hence the temperature could be controlled by controlling the diluting gas amount, in this case, the over heat of bath refractory could be prevented and the lifetime of refractory could be extended.

ASTM A 588

Alloy Digest ◽  
1991 ◽  
Vol 40 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Tensile Properties ◽  
Alloy Steel ◽  
Heat Treating ◽  
High Alloy ◽  
High Alloy Steel ◽  
Bethlehem Steel Corporation ◽  
Steel Grades ◽  
Steel Corporation ◽  
Low Strength

Abstract ASTM A588 covers low strength, high-alloy steel grades. They are used primarily in boldly exposed situations, architecturally without painting. These steels are commonly referred to as weathering steels. This datasheet provides information on composition and tensile properties. It also includes information on corrosion resistance as well as heat treating and joining. Filing Code: SA-460. Producer or source: Bethlehem Steel Corporation.

scholarly journals RATIONAL FOR REHEATING IN THE AUTOMATED LINE FOR RING BLANKS PRODUCTION

2021 ◽  
Vol 3 (56) ◽  
pp. 61-69
Author(s):  
Vladimir E. ANTONYUK ◽  
◽  
Sergey O. NIKIFOROVICH ◽  
Victor V. RUDII ◽  
◽  
...  
Keyword(s):  
Wall Thickness ◽  
Ring Rolling ◽  
Complex Profile ◽  
High Alloy ◽  
Technological Support ◽  
Additional Heating ◽  
Temperature State ◽  
Alloy Steels ◽  
Automated Line ◽  
High Alloy Steels

Features and requirements to the use of reheating of ring blanks in the conditions of production on the automated line are considered. An assessment is given for a technological temperature state of ring blanks at various stages of production under conditions of the automated line. For assessment of rational for reheating at production of ring blanks, a classification of ring manufacturing technology is proposed with the production of a pressed non-core blank in an open die, with the production of a pressed profile blank in a closed die, with the production of a pressed profile blank in a stamp with reverse extrusion. The technology of ring rolling with the production of a pressed non-core blank in an open die is the most economical and does not require the use of reheating in the manufacture of rings made of medium-alloy steels. The technology of ring rolling of a profile blank obtained in a closed die does not require the use of additional heating after pressing, in the case of manufacturing rings with a simplified profile on the outer or inner diameters of the ring. In the manufacture of rings with a more complex profile on the outer and inner diameters of the ring, as well as rings made of high-alloy steels, the final decision on the need for additional heating is made depending on the temperature of the end of intensive plastic deformation for the selected steel grade of the ring. The technology of ring rolling with the production of a pressed profile blank in a die with reverse extrusion requires the use of reheating after the pressing operation before the ring rolling operation, and is recommended for the manufacture of rings from medium- and high-alloy steels with a complex profile section on the outer and inner diameters, wall thicknesses, with a ratio of wall thickness to outer diameter D within h / D = 0.011...0.016 and with a ratio of wall thickness to ring height L within h / L = 0.020...0.041. The proposed recommendations are intended for use in the development of technological support for the operation of the automated ring-rolling complex at OJSC “BELAZ”.

scholarly journals Impact of Solidification on Inclusion Morphology in ESR and PESR Remelted Martensitic Stainless Steel Ingots

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 408
Author(s):  
Ewa Sjöqvist Persson ◽  
Sofia Brorson ◽  
Alec Mitchell ◽  
Pär G. Jönsson
Keyword(s):  
Stainless Steel ◽  
Martensitic Stainless Steel ◽  
Dendritic Structure ◽  
Steel Grade ◽  
Solidification Structure ◽  
Production Scale ◽  
Steel Grades ◽  
Steel Ingots ◽  
Columnar Dendritic Structure ◽  
The Impact

This study focuses on the impact of solidification on the inclusion morphologies in different sizes of production-scale electro-slag remelting (ESR) and electro-slag remelting under a protected pressure-controlled atmosphere, (PESR), ingots, in a common martensitic stainless steel grade. The investigation has been carried out to increase the knowledge of the solidification and change in inclusion morphologies during ESR and PESR remelting. In order to optimize process routes for different steel grades, it is important to define the advantages of different processes. A comparison is made between an electrode, ESR, and PESR ingots with different production-scale ingot sizes, from 400 mm square to 1050 mm in diameter. The electrode and two of the smallest ingots are from the same electrode charge. The samples are taken from both the electrode, ingots, and rolled/forged material. The solidification structure, dendrite arm spacing, chemical analyzes, and inclusion number on ingots and/or forged/rolled material are studied. The results show that the larger the ingot and the further towards the center of the ingot, the larger inclusions are found. As long as an ingot solidifies with a columnar dendritic structure (DS), the increase in inclusion number and size with ingot diameter is approximately linear. However, at the ingot size (1050 mm in diameter in this study) when the center of the ingot converts to solidification in the equiaxial mode (EQ), the increase in number and size of the inclusions is much higher. The transition between a dendritic and an equiaxial solidification in the center of the ingots in this steel grade takes place in the region between the ingot diameters of 800 and 1050 mm.

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