Phase proportions, carbon equivalent, mechanical properties and their effect on material cost of railway axle steels

MRS Advances ◽  
2018 ◽  
Vol 3 (37) ◽  
pp. 2169-2181
Author(s):  
D.E.P. Klenam ◽  
L.H. Chown ◽  
M.J. Papo ◽  
L.A. Cornish
Keyword(s):  
High Speed ◽  
Hsla Steel ◽  
Weight Fraction ◽  
Carbon Steels ◽  
Carbon Equivalent ◽  
Medium Carbon ◽  
Railway Axle ◽  
Material Costs ◽  
Material Cost ◽  
Hsla Steels

AbstractCommuter trains with solid axle configuration are produced from medium carbon steel due to cost restrictions. High-speed trains have hollow axle configuration for reduced weight and are made from high strength low-alloy (HSLA) steels. The HSLA steels have higher amounts of C, Cr, Ni, Mo, V and Nb, and are more expensive than medium carbon steels. The effects of phase proportions, carbon equivalent (CE), yield strength and ultimate tensile strength (UTS) on material costs of existing railway axle steels were studied using Thermo-Calc. Medium carbon rail axle steels had higher Fe3C phase proportions than the HSLA steel rail axle grades. Higher affinity of Cr, Mo and V for C than Fe resulted in decreased cementite proportions. The HSLA steels had yield strengths above 370 MPa, and UTS above 750 MPa, with increased material cost above $3300 per ton. A scattered distribution was observed for the pearlite weight fraction and material costs, with most between $3200 and $3400. The yield and tensile strengths increased with increasing carbon equivalent and pearlite weight fraction. The data aided the selection and design of alloys with better mechanical and corrosion properties at reduced material cost.

Improving the efficiency of metal-bonded diamond abrasive end tools by improving manufacturing technology

2021 ◽  
Vol 23 (2) ◽  
pp. 66-80
Author(s):  
Valentin Smirnov ◽  
◽  
Dmitry Lobanov ◽  
Vadim Skeeba ◽  
Ivan Golyushov ◽  
...  
Keyword(s):  
High Speed ◽  
High Speed Steel ◽  
Carbon Steels ◽  
Manufacturing Technology ◽  
The Body ◽  
Processing Technologies ◽  
Medium Carbon ◽  
The Cost ◽  
Diamond Abrasive ◽  
Bearing Part

Introduction. Difficult-to-machine materials with enhanced physical and mechanical properties are increasingly being used in various industries. Such materials are used in mechanical engineering for the manufacture of parts and assemblies of machines and mechanisms, in the production and processing of food products where increased operational requirements are required. In modern production, along with traditional methods of intensifying technological operations, combined and hybrid processing technologies are used. For the finishing of products, abrasive grinding with a diamond tool is used. One of the problems hindering the wide practical application of this method in industry is the fact that it has a high prime cost caused by the cost of materials used in the manufacture and the laboriousness of the tool shaping process. This leads to the need to develop a new technology for manufacturing diamond tools. The purpose of the work is to increase the efficiency of the end diamond abrasive tool with a metal bond by using carbon steels as a body material, increasing the strength of the connection between the body and the diamond-bearing part, as well as choosing an effective tool manufacturing technology. Research methodology. To gain this task, a technology for manufacturing end diamond abrasive tools is developed and tested. Allowing using the technology of capacitor welding to connect the diamond-bearing part with the shank and use medium-carbon hardened high-quality steels with a hardness of 45-60 HRC as the shank material. The strength of the connection of the body with the working diamond-bearing part of the grinding head samples is determined by tensile testing on a 1958U10 tensile machine with maximum load 100 kN. The quality of the joint is assessed visually by the presence of discontinuities in the joint, as well as by examining the microstructure and measuring the microhardness of the weld and heat-affected zones. The microhardness of the welded joint is measured using an HMV-G21ST semi-automatic microhardness tester (Shimadzu, Japan) at a load of 50 g. Results and discussion. Thus, the results of comparative studies allow us to assert that the strength of the connection between the shank and the working diamond-bearing part according to the proposed technology surpasses similar characteristics of the strength of the connection between the shank and the diamond-bearing layer of grinding heads obtained by the method selected by the prototype. Conclusions. The proposed technology for the manufacture of diamond heads increases the strength of the connection between the body and the diamond-bearing working part, reduces the cost of manufacturing the grinding heads due to the use of hardened medium-carbon steels as the material of the tool body instead of high-speed steel grades, the technology is simplified and the possibility of automating the manufacture of tools appears.

Issues in Welding of HSLA Steels

2011 ◽  
Vol 365 ◽  
pp. 44-49 ◽  
Author(s):  
Sandeep Jindal ◽  
Rahul Chhibber ◽  
N.P. Mehta
Keyword(s):  
Structural Integrity ◽  
Hsla Steel ◽  
Weight Ratio ◽  
Welding Process ◽  
Pressure Vessels ◽  
Carbon Steels ◽  
Low Carbon ◽  
Line Pipe ◽  
Hsla Steels ◽  
Selection Of

The application of High Strength Low Alloy (HSLA) steels has expanded to almost all fields viz. automobile industry, ship building, line pipe, pressure vessels, building construction, bridges, storage tanks. HSLA steels were developed primarily for the automotive industry to replace low-carbon steels in order to improve the strength-to-weight ratio and meet the need for higher-strength materials. Due to higher-strength and added excellent toughness and formability, demand for HSLA steel is increasing globally. With the increase of demand; other issues like the selection of filler grade and selection of suitable welding process for the joining of these steels have become very significant. This paper discusses the various issues regarding selection of suitable grade and selection of suitable welding process for joining of HSLA steels and issues concerning the structural integrity of HSLA steel welds.

Study of medium-carbon steels structure after electromechanical processing

2020 ◽  
pp. 473-477
Author(s):  
Yu.S. Ivanova ◽  
V.N. Zaripov ◽  
Ngo Van Tuyen ◽  
Myat Soe Lwin ◽  
Ye Kyaw Oo
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
Heat Stability ◽  
Carbon Steels ◽  
Original Structure ◽  
Surface Microhardness ◽  
Medium Carbon ◽  
Wide Range ◽  
Medium Carbon Steels ◽  
40Cr Steel

The results of the microstructure and microhardness of the surface layer of medium-carbon 40Cr, 38CrNi3MoA steels after electromechanical processing are presented. The results of tests on the heat stability of samples made of 38CrNi3MoA steel when they are consistently heated from 150 to 550 °C, in the temperature range of 50 °C are presented. The samples are heated in muffle furnaces with exposure at each temperature of 10 min and cooled in air. The heat stability of the surface layer after electromechanical processing is controlled by changes in microhardness. The results of the microstructure indicate the formation of fine martensite and retained austenite in the upper layers of the quenching zones. High speed heating of local volume of the surface with parallel thermoplastic shaping by work-hardening tool and following high-intensity cooling through heat rejection in deep into work material take place in the time of electromechanical processing. The structure of sorbite is form in the overlap zone of electro-mechanical hardening and in the transition near original structure section. The average surface microhardness of the 40Cr steel samples before hardening is HV = 2000...2400 MPa, after electromechanical hardening — HV = 6640 MPa, and the 38CrNi3MoA steel samples before hardening is HV = 2000...2200 MPa, after electromechanical hardening — HV = 7060 MPa. The graded layer has hardening depth to 0.8 mm with stepwise degradation of hardness is detected. The research results show that using electromechanical processing in the manufacture of wide range of parts in order to increase the wear resistance of the surface layer.

Quantification of Vanadium Precipitates after Reheating Slab Steel by Synchrotron X-Ray Absorption Spectroscopy (XAS)

2017 ◽  
Vol 728 ◽  
pp. 20-25
Author(s):  
Audtaporn Worabut ◽  
Nirawat Thammajak ◽  
Hans Henning Dickert ◽  
Piyada Suwanpinij
Keyword(s):  
Hsla Steel ◽  
Dissolution Kinetics ◽  
High Strength ◽  
Rolling Process ◽  
Solubility Limit ◽  
Carbon Steels ◽  
Microalloyed Steels ◽  
Hsla Steels ◽  
Microalloying Elements ◽  
X Ray Absorption

High Strength Low Alloy (HSLA) steels or microalloyed steels are developed in order toimprove the strength and toughness compared with conventional carbon steels. During the reheatingprocess at 1250-1300 °C for a few hours, the furnace consumes large amount of energy, and the slabsuffers from thick oxide scale. This results in significant mass loss. The long reheating time ensuresmaximum dissolution of the microalloying elements, which must be kept to precipitate duringcooling at the end of the hot rolling process. To minimise the reheating time and save the energyconsumption, this research studied the dissolution kinetics of vanadium in HSLA steel. Vanadium isa main microalloying element added to provide higher strength mainly by precipitation hardening. Itis supposed to be dissolved readily according to the solubility limit. The samples were reheated to1200 °C and 1250 °C for 0, 10, 30, and 60 s. After that the fraction of vanadium dissolved in the solidsolution and the remaining undissolved phases of VC, CN, and V(C,N) were measured bysynchrotron XAS. As soon as the sample reaches as low temperature as 1200 °C, a large atomicfraction of 0.878 of vanadium can be dissolved in the solid solution.

Observations on the structure at the transformation interface of pearlite in steel

1990 ◽  
Vol 48 (4) ◽  
pp. 200-201
Author(s):  
F. A. Khalid ◽  
D. V. Edmonds
Keyword(s):  
Room Temperature ◽  
Thin Foil ◽  
Carbon Steels ◽  
Model Alloy ◽  
Growth Interface ◽  
Medium Carbon ◽  
Solution Treated ◽  
Medium Carbon Steels ◽  
Alloy Carbide ◽  
Hot Rolled

The austenite/pearlite growth interface in a model alloy steel (Fe-1 lMn-0.8C nominal wt%) is being investigated. In this particular alloy pearlite nodules can be grown isothermally in austenite that remains stable at room temperature, thus facilitating examination of the transformation interfaces. This study presents preliminary results of thin foil TEM of the austenite/pearlite interface, as part of a programme of aimed at studying alloy carbide precipitation reactions at this interface which can result in significant strengthening of microalloyed low- and medium- carbon steels L Similar studies of interface structure, made on a partially decomposed high- Mn austenitic alloy, have been reported recently.The experimental alloys were made as 50 g argon arc melts using high purity materials and homogenised. Samples were hot- rolled, swaged and machined to 3mm diameter rod, solution treated at 1300 °C for 1 hr and WQ. Specimens were then solutionised between 1250 °C and 1000 °C and isothermally transformed between 610 °C and 550 °C for 10-18 hr and WQ.

Precipitation at the transformation interface of pearlite in steel

1990 ◽  
Vol 48 (4) ◽  
pp. 912-913
Author(s):  
F. A. Khalid ◽  
D. V. Edmonds
Keyword(s):  
Thin Foil ◽  
Carbon Steels ◽  
Model Alloy ◽  
Low Carbon ◽  
High Carbon ◽  
Growth Interface ◽  
Medium Carbon ◽  
Interphase Precipitation ◽  
Solution Treated ◽  
Wide Range

The austenite/pearlite growth interface in a model alloy steel (Fe-1lMn-0.8C-0.5V nominal wt%) is being studied in an attempt to characterise the morphology and mechanism of VC precipitation at the growth interface. In this alloy pearlite nodules can be grown isothermally in austenite that remains stable at room temperature thus facilitating examination of the transformation interfaces. This study presents preliminary results of thin foil TEM of the precipitation of VC at the austenite/ferrite interface, which reaction, termed interphase precipitation, occurs in a number of low- carbon HSLA and microalloyed medium- and high- carbon steels. Some observations of interphase precipitation in microalloyed low- and medium- carbon commercial steels are also reported for comparison as this reaction can be responsible for a significant increase in strength in a wide range of commercial steels.The experimental alloy was made as 50 g argon arc melts using high purity materials and homogenised. Samples were solution treated at 1300 °C for 1 hr and WQ. Specimens were then solutionised at 1300 °C for 15 min. and isothermally transformed at 620 °C for 10-18hrs. and WQ. Specimens of microalloyed commercial steels were studied in either as-rolled or as- forged conditions. Detailed procedures of thin foil preparation for TEM are given elsewhere.

FROSTLINE

Alloy Digest ◽  
1977 ◽  
Vol 26 (3) ◽  
Keyword(s):  
Structural Design ◽  
Heat Treating ◽  
Carbon Steels ◽  
Carbon Equivalent ◽  
Low Carbon ◽  
Steel Company ◽  
Cold Temperatures ◽  
Fine Grain ◽  
Design Requirements ◽  
Treated Carbon

Abstract FROSTLINE is a fine-grain, columbium-treated carbon steel designed to be an economical solution to structural design requirements at cold temperatures. Available in plate thicknesses up to 6 inches, it offers high levels of toughness at temperatures to 80 F and higher strength levels than conventional carbon steels. Frostline also offers excellent welding characteristics, because of its low carbon equivalent. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: CS-67. Producer or source: Lukens Steel Company.

INCO-WELD C

Alloy Digest ◽  
1996 ◽  
Vol 45 (1) ◽  
Keyword(s):  
Tensile Properties ◽  
Stainless Steels ◽  
Arc Welding ◽  
Carbon Steels ◽  
Alloy Electrode ◽  
Shielded Metal Arc Welding ◽  
Medium Carbon ◽  
Metal Arc Welding ◽  
Spring Steels ◽  
Medium Carbon Steels

Abstract INCO WELD C Electrode is a stainless-alloy electrode especially designed for shielded-metal-arc welding of a broad range of materials, including many difficult-to-weld compositions. It can be used in stainless steels, mild and medium-carbon steels,and spring steels. This datasheet provides information on composition, hardness, and tensile properties. It also includes information on joining. Filing Code: SS-632. Producer or source: Inco Alloys International Inc.

Influence of post-welding tempering on mechanical behavior of friction welded joints from medium-carbon steels during tensile test

2020 ◽  
pp. 40-49
Author(s):  
A. S. Atamashkin ◽  
E. Yu. Priymak ◽  
N. V. Firsova
Keyword(s):  
Mechanical Behavior ◽  
Welded Joints ◽  
Welded Joint ◽  
Crack Nucleation ◽  
Carbon Steels ◽  
Uniaxial Tensile ◽  
Medium Carbon ◽  
Uniaxial Tensile Testing ◽  
Rotary Friction Welding ◽  
Medium Carbon Steels

The paper presents an analysis of the mechanical behavior of friction samples of welded joints from steels 30G2 (36 Mn 5) and 40 KhN (40Ni Cr 6), made by rotary friction welding (RFW). The influence of various temperature conditions of postweld tempering on the mechanical properties and deformation behavior during uniaxial tensile testing is analyzed. Vulnerabilities where crack nucleation and propagation occurred in specimens with a welded joint were identified. It was found that with this combination of steels, postweld tempering of the welded joint contributes to a decrease in the integral strength characteristics under conditions of static tension along with a significant decrease in the relative longitudinal deformation of the tested samples.

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