8 Weldability of 17-4 PH stainless steel for centrifugal compressor impeller was considered. Weld... more 8 Weldability of 17-4 PH stainless steel for centrifugal compressor impeller was considered. Welding tests were carried out on the precipitation-hardened steel of the 17-4 PH type. Possibilities of joining centrifugal compressor impeller parts as important elements of turbo machines were considered. Two means of welding (1 1 1) and (1 1 4), as well as following heat treatment have been considered. The best results: high tensile strength and high corrosion resistance were obtained for saturating for the wheels welded in temperature 1313 K/2 h followed by ageing in 893 K/2 h or only annealed for stress reliving in temperature 893 K/2 h after welding.
ABSTRACT The relationship between iron phosphide layer growth parameters, their structure and pro... more ABSTRACT The relationship between iron phosphide layer growth parameters, their structure and properties were considered. The layers were generated on a base of Armco iron and 0.4% C, 1.1% Cr steel as a result of annealing in a mixture of argon and phosphorus vapours. Mechanism and kinetics of iron phosphide layer growth was described. It is possible to obtain a layer of Fe3P+Fe2P phosphides and a solid solution of phosphorus in iron. Iron phosphide layer increases the hardness and the friction wear resistance of iron alloys.
ABSTRACT Stresses in brazing joints of different differed in properties were appraised as a resul... more ABSTRACT Stresses in brazing joints of different differed in properties were appraised as a result of technological experiments and FEM analysis. Evaluation of microstructure and mechanical properties of large dimensional vacuum brazed joints of Ferro Titanit Nicro 128 sinters and precipitation hardened stainless steel of X5CrNiMoCuNb14-5 using copper as the brazing filler metal. Structure of the joint was described. Shear strength Rt and tensile strength Rm of the joints have been defined. It have been state, that the basic factors decreasing quality of the joint, which can occur during vacuum brazing of the Ferro Titanit Nicro 128 sinter Cu brazing filler metal steel joints are diffusive processes leading to exchange of the cermets and brazing filler metal elements and creation of intermetallic in the joint. It can have an unfavourable influence on ductility and quality of the joint. The effect of joint geometry structure on stresses and deformations as well as on the process of plate cracking has been determined. Results of numerical calculations of three-dimensional models of brazed joints for different sizes of surfaces brazed at a constant width of solder gap are presented. Results of the investigate proved that joints microstructure and mechanical properties depend on filler and parent materials, diffusion process during brazing, leading to exchange of the cermets components and filler metal as well as joint geometry. The thickness of the joints has an essential influence on the values of the local stress and the significant influence on the joint rigidity. In a case of the considered joints the values of the local stress differences have been considerable in dependence of a fixed load manner.
Results of tribological tests on Armco iron after gaseous phosphorizing treatment are presented. ... more Results of tribological tests on Armco iron after gaseous phosphorizing treatment are presented. As a result of the phosphorizing process, the diffusive layers of the iron phosphides Fe2P and Fe3P, with structure defined by selection of the process parameters, have been formed on the iron surface. It has been proved that the presence of the iron phosphides in the surface layer improves the tribological properties of iron. The optimization of the gaseous phosphorizing parameters has been carried out while assuming minimum wear and dry sliding friction coefficient as optimization criteria. A proposed explanation of the dry friction mechanism occurring between the phosphorized surface and the steel surface is given.
Purpose: of this paper was to select interfacial materials to provide friction coefficients less ... more Purpose: of this paper was to select interfacial materials to provide friction coefficients less than ÎĽ= 0.3 whichremain at this level during the machine lifetime. This material must withstand cycling motion under pressuresup to 80 MPa, at 77 K, and in vacuum of 10-4 Pa.Design/methodology/approach: In the described work, experiments were conducted to determine the frictioncoefficient and the wear of several low friction materials. The test rig consists of a cryogenic sample holderenclosed in vacuum chamber installed into a servo-hydraulic test machine (M.T.S.). The friction coefficientshave been measured cycling the samples (1,960 mm2) for about 38,000 cycles at normal pressure up to 80 MPa,sliding speed of 0.1 m/min, at 77 K, and under vacuum of 10-4 Pa.Findings: The Fiberslip B40 (woven multifilament of PTFE and glass) was selected as the best candidatematerial. It exhibited a friction coefficient of approximately ÎĽ = 0.22, and low wear rate was obtained. Themaximum value of the f...
Purpose: Purpose of this paper is description of influence of the heat input of submerged arc wel... more Purpose: Purpose of this paper is description of influence of the heat input of submerged arc welding (SAW) of duplex steel UNS S31803 on welded butt joints corrosion resistance.Design/methodology/approach: Butt joints on plates of 9 – 30 mm thickness were executed where the applied heat input of welding exceeded the 2.5 kJ/mm value. Maximum heat input level was HI ≤ 3.0; HI ≤ 3.5; HI ≤ 4.0; HI ≤ 4.5; HI ≤ 5.0. Analysis of welding heat input influence on mechanical properties, value of ferrite share, and corrosion of test joints has been done. Non-destructive and destructive testing, e. g. visual examinations, microstructure examination, corrosion resistance tests according to ASTM G48 Method A, HV5 hardness tests, impact and tensile test were carried out. For analysis of welding heat input influence on creation of welding imperfections, there were executed welding of sheet of thickness 9, 14, 28 mm.Findings: It was shown that submerged arc welding of duplex steel with the heat inpu...
Purpose: of this paper is study of structure properties of considerable surfaces vacuum brazed jo... more Purpose: of this paper is study of structure properties of considerable surfaces vacuum brazed joints of WC-Co sinters and precipitation hardened stainless steel of 14-5 PH using copper and silver-copper as the brazing filler metal.Design/methodology/approach: the joints are used in large dimension spinning nozzles of a die for polyethylene granulation, in that considerable strength and ductility of the joints are required. Structure and mechanical properties of joints have been described. Shear strength Rt and tensile strength Rm of the joints have been defined.Findings: to have been state, that the basic factors decreasing quality of the joint, which can occur during vacuum brazing of the WC-Co ISO K05 sinter – Cu or Ag-Cu brazing filler metal – 14-5 PH steel joints are diffusive processes leading to exchange of elements of cermets and the brazing filler metal and creation of intermetalics in the joint. It can have an unfavourable influence on ductility of sinters and quality of j...
Purpose: Purpose consideration of role of phosphorus in iron alloys surface engineering and relat... more Purpose: Purpose consideration of role of phosphorus in iron alloys surface engineering and relations of the iron phosphides layers growth parameters in processes of phosphorising, phosphorcarburising, and phosphonitriding with their structure and properties.Design/methodology/approach: The layers were generated on a base of Armco iron and 0.4%C, 1.1%Cr steel as a result of annealing in a mixture of argon or carburising, nitriding atmosphere and phosphorus vapours in: temperature T = 700 - 1170 K, phosphorus partial pressure p = 0.1 - 20 kPa, process duration t = 3.6 - 21.6 ks. The diffusion layers were investigated by means of the methods: metallographic, X - ray structural analysis, microanalysis, Vickers and wear dry friction resistance tests.Findings: Formation of compact layer of phosphides with the adjustable relation of Fe3P to Fe2P was described; means of growth and kinetics of iron phosphides layers and phosphocarburised and phosphonitrided were explained, it was found that...
Purpose: On the basis of sources and own experiments, the analysis of microstructure, properties,... more Purpose: On the basis of sources and own experiments, the analysis of microstructure, properties, applications as well as material and technological problems of ferritic-austenitic steel welding were carried out. It was shown the area of welding applications, particularly welding of large-size structures, on the basis of example of the FCAW method of welding of the UNS S3 1803 duplex steel in construction of chemical cargo ships.Design/methodology/approach: Influence of selected aspects of welding technology, including welding heat input and between-bead temperature, additional materials on microstructure transitions and properties of welded joints were analysed. In the described work, experiments were conducted to welding tests for selected joints, visual examinations, non-destructive testing of welded joints, X-ray examinations, and metallographic testing of welded joints.Findings: As a result of the performed inspection, decreasing of the ferrite content with the increase of the ...
Purpose: The paper aimed at determining the strength of modified bone cement microstructure. Modi... more Purpose: The paper aimed at determining the strength of modified bone cement microstructure. Modification with aqueous hormone solution stimulates the growth of bone at a hip-joint endoprosthesis implantation site.Design/methodology/approach: In the first place, microstructure of modified cements was examined. This examination was a basis for statistical description of porosity obtained as a result of modification. Statistical data were used to create microstructure models in a programme being in agreement with FEM technique. Simulations were carried out on structures of 2 types of pores, i.e. those containing water and empty ones.Findings: Modification with aqueous solutions of modifying agents affects the structure and properties of bone cements. This is caused by formation of pores filled with aqueous solutions of modifying agents. This type of porosity decreases mechanical properties less than air-filled pores.Research limitations/implications: Numerical simulation of the stress...
This paper presents the results of cutting aluminum foams. The experiment includes the following ... more This paper presents the results of cutting aluminum foams. The experiment includes the following mechanical methods of cutting: circular saw cutting, band-saw cutting, EDM cutting, water-jet cutting, and thermal cutting methods: laser cutting and air plasma cutting. The influence of the cutting method on the edge geometry was specified in the paper. EDM was defined as the most advantageous method of Al foam cutting, as providing the best aluminium foam edges surface quality for welding.
Purpose: this paper was to determine the impact of the wide-gap welding, with increased root face... more Purpose: this paper was to determine the impact of the wide-gap welding, with increased root face gap, on structure and corrosion properties of the welded joints executed on duplex steel by one-side welding on ceramic backings.Design/methodology/approach: In the described work, experiments were conducted to welding tests for selected joints, visual examinations, non-destructive testing of welded joints, X-ray examinations, and metallographic testing of welded joints.Findings: As a result of the performed inspection, decreasing of the ferrite content with the increase of the root face gap (increase of welding heat input) was observed. The minimum measured ferrite content was not lower than 28 %, and the maximum value did not exceed 69% (the permissible range being from 25 to 70 %).Research limitations/implications: Further studies on the impact of the wide-gap welding, with increased root face gap, on structure and corrosion properties of the welded joints are required.Practical impl...
Purpose: test if the welding heat input exceeding the recommended values has negative impact on s... more Purpose: test if the welding heat input exceeding the recommended values has negative impact on strength properties and corrosion resistance of the executed welded joints as well as description of influence of the heat input of submerged arc welding (SAW) of duplex steel UNS S31803 (0.032%C, 23.17%Cr, 9.29%Ni, 3.48%Mo, 0.95%Mn, 0.7%Si, 0.16%N, 0.017P, 0.006%S, 0.11%Cu) on welded joints microstructure, particularly average values of ferrite volume fraction, mechanical properties, and corrosion resistance.Design/methodology/approach: analysis of welding heat input influence on mechanical properties, value of ferrite share, and corrosion of test joints has been done. Non-destructive and destructive testing, e. g. visual examinations, microstructure examination, corrosion resistance tests according to ASTM G48 Method A, HV5 hardness tests, impact and tensile test were carried out. For analysis of welding heat input influence on creation of welding imperfections, there were executed weld...
8 Weldability of 17-4 PH stainless steel for centrifugal compressor impeller was considered. Weld... more 8 Weldability of 17-4 PH stainless steel for centrifugal compressor impeller was considered. Welding tests were carried out on the precipitation-hardened steel of the 17-4 PH type. Possibilities of joining centrifugal compressor impeller parts as important elements of turbo machines were considered. Two means of welding (1 1 1) and (1 1 4), as well as following heat treatment have been considered. The best results: high tensile strength and high corrosion resistance were obtained for saturating for the wheels welded in temperature 1313 K/2 h followed by ageing in 893 K/2 h or only annealed for stress reliving in temperature 893 K/2 h after welding.
ABSTRACT The relationship between iron phosphide layer growth parameters, their structure and pro... more ABSTRACT The relationship between iron phosphide layer growth parameters, their structure and properties were considered. The layers were generated on a base of Armco iron and 0.4% C, 1.1% Cr steel as a result of annealing in a mixture of argon and phosphorus vapours. Mechanism and kinetics of iron phosphide layer growth was described. It is possible to obtain a layer of Fe3P+Fe2P phosphides and a solid solution of phosphorus in iron. Iron phosphide layer increases the hardness and the friction wear resistance of iron alloys.
ABSTRACT Stresses in brazing joints of different differed in properties were appraised as a resul... more ABSTRACT Stresses in brazing joints of different differed in properties were appraised as a result of technological experiments and FEM analysis. Evaluation of microstructure and mechanical properties of large dimensional vacuum brazed joints of Ferro Titanit Nicro 128 sinters and precipitation hardened stainless steel of X5CrNiMoCuNb14-5 using copper as the brazing filler metal. Structure of the joint was described. Shear strength Rt and tensile strength Rm of the joints have been defined. It have been state, that the basic factors decreasing quality of the joint, which can occur during vacuum brazing of the Ferro Titanit Nicro 128 sinter Cu brazing filler metal steel joints are diffusive processes leading to exchange of the cermets and brazing filler metal elements and creation of intermetallic in the joint. It can have an unfavourable influence on ductility and quality of the joint. The effect of joint geometry structure on stresses and deformations as well as on the process of plate cracking has been determined. Results of numerical calculations of three-dimensional models of brazed joints for different sizes of surfaces brazed at a constant width of solder gap are presented. Results of the investigate proved that joints microstructure and mechanical properties depend on filler and parent materials, diffusion process during brazing, leading to exchange of the cermets components and filler metal as well as joint geometry. The thickness of the joints has an essential influence on the values of the local stress and the significant influence on the joint rigidity. In a case of the considered joints the values of the local stress differences have been considerable in dependence of a fixed load manner.
Results of tribological tests on Armco iron after gaseous phosphorizing treatment are presented. ... more Results of tribological tests on Armco iron after gaseous phosphorizing treatment are presented. As a result of the phosphorizing process, the diffusive layers of the iron phosphides Fe2P and Fe3P, with structure defined by selection of the process parameters, have been formed on the iron surface. It has been proved that the presence of the iron phosphides in the surface layer improves the tribological properties of iron. The optimization of the gaseous phosphorizing parameters has been carried out while assuming minimum wear and dry sliding friction coefficient as optimization criteria. A proposed explanation of the dry friction mechanism occurring between the phosphorized surface and the steel surface is given.
Purpose: of this paper was to select interfacial materials to provide friction coefficients less ... more Purpose: of this paper was to select interfacial materials to provide friction coefficients less than ÎĽ= 0.3 whichremain at this level during the machine lifetime. This material must withstand cycling motion under pressuresup to 80 MPa, at 77 K, and in vacuum of 10-4 Pa.Design/methodology/approach: In the described work, experiments were conducted to determine the frictioncoefficient and the wear of several low friction materials. The test rig consists of a cryogenic sample holderenclosed in vacuum chamber installed into a servo-hydraulic test machine (M.T.S.). The friction coefficientshave been measured cycling the samples (1,960 mm2) for about 38,000 cycles at normal pressure up to 80 MPa,sliding speed of 0.1 m/min, at 77 K, and under vacuum of 10-4 Pa.Findings: The Fiberslip B40 (woven multifilament of PTFE and glass) was selected as the best candidatematerial. It exhibited a friction coefficient of approximately ÎĽ = 0.22, and low wear rate was obtained. Themaximum value of the f...
Purpose: Purpose of this paper is description of influence of the heat input of submerged arc wel... more Purpose: Purpose of this paper is description of influence of the heat input of submerged arc welding (SAW) of duplex steel UNS S31803 on welded butt joints corrosion resistance.Design/methodology/approach: Butt joints on plates of 9 – 30 mm thickness were executed where the applied heat input of welding exceeded the 2.5 kJ/mm value. Maximum heat input level was HI ≤ 3.0; HI ≤ 3.5; HI ≤ 4.0; HI ≤ 4.5; HI ≤ 5.0. Analysis of welding heat input influence on mechanical properties, value of ferrite share, and corrosion of test joints has been done. Non-destructive and destructive testing, e. g. visual examinations, microstructure examination, corrosion resistance tests according to ASTM G48 Method A, HV5 hardness tests, impact and tensile test were carried out. For analysis of welding heat input influence on creation of welding imperfections, there were executed welding of sheet of thickness 9, 14, 28 mm.Findings: It was shown that submerged arc welding of duplex steel with the heat inpu...
Purpose: of this paper is study of structure properties of considerable surfaces vacuum brazed jo... more Purpose: of this paper is study of structure properties of considerable surfaces vacuum brazed joints of WC-Co sinters and precipitation hardened stainless steel of 14-5 PH using copper and silver-copper as the brazing filler metal.Design/methodology/approach: the joints are used in large dimension spinning nozzles of a die for polyethylene granulation, in that considerable strength and ductility of the joints are required. Structure and mechanical properties of joints have been described. Shear strength Rt and tensile strength Rm of the joints have been defined.Findings: to have been state, that the basic factors decreasing quality of the joint, which can occur during vacuum brazing of the WC-Co ISO K05 sinter – Cu or Ag-Cu brazing filler metal – 14-5 PH steel joints are diffusive processes leading to exchange of elements of cermets and the brazing filler metal and creation of intermetalics in the joint. It can have an unfavourable influence on ductility of sinters and quality of j...
Purpose: Purpose consideration of role of phosphorus in iron alloys surface engineering and relat... more Purpose: Purpose consideration of role of phosphorus in iron alloys surface engineering and relations of the iron phosphides layers growth parameters in processes of phosphorising, phosphorcarburising, and phosphonitriding with their structure and properties.Design/methodology/approach: The layers were generated on a base of Armco iron and 0.4%C, 1.1%Cr steel as a result of annealing in a mixture of argon or carburising, nitriding atmosphere and phosphorus vapours in: temperature T = 700 - 1170 K, phosphorus partial pressure p = 0.1 - 20 kPa, process duration t = 3.6 - 21.6 ks. The diffusion layers were investigated by means of the methods: metallographic, X - ray structural analysis, microanalysis, Vickers and wear dry friction resistance tests.Findings: Formation of compact layer of phosphides with the adjustable relation of Fe3P to Fe2P was described; means of growth and kinetics of iron phosphides layers and phosphocarburised and phosphonitrided were explained, it was found that...
Purpose: On the basis of sources and own experiments, the analysis of microstructure, properties,... more Purpose: On the basis of sources and own experiments, the analysis of microstructure, properties, applications as well as material and technological problems of ferritic-austenitic steel welding were carried out. It was shown the area of welding applications, particularly welding of large-size structures, on the basis of example of the FCAW method of welding of the UNS S3 1803 duplex steel in construction of chemical cargo ships.Design/methodology/approach: Influence of selected aspects of welding technology, including welding heat input and between-bead temperature, additional materials on microstructure transitions and properties of welded joints were analysed. In the described work, experiments were conducted to welding tests for selected joints, visual examinations, non-destructive testing of welded joints, X-ray examinations, and metallographic testing of welded joints.Findings: As a result of the performed inspection, decreasing of the ferrite content with the increase of the ...
Purpose: The paper aimed at determining the strength of modified bone cement microstructure. Modi... more Purpose: The paper aimed at determining the strength of modified bone cement microstructure. Modification with aqueous hormone solution stimulates the growth of bone at a hip-joint endoprosthesis implantation site.Design/methodology/approach: In the first place, microstructure of modified cements was examined. This examination was a basis for statistical description of porosity obtained as a result of modification. Statistical data were used to create microstructure models in a programme being in agreement with FEM technique. Simulations were carried out on structures of 2 types of pores, i.e. those containing water and empty ones.Findings: Modification with aqueous solutions of modifying agents affects the structure and properties of bone cements. This is caused by formation of pores filled with aqueous solutions of modifying agents. This type of porosity decreases mechanical properties less than air-filled pores.Research limitations/implications: Numerical simulation of the stress...
This paper presents the results of cutting aluminum foams. The experiment includes the following ... more This paper presents the results of cutting aluminum foams. The experiment includes the following mechanical methods of cutting: circular saw cutting, band-saw cutting, EDM cutting, water-jet cutting, and thermal cutting methods: laser cutting and air plasma cutting. The influence of the cutting method on the edge geometry was specified in the paper. EDM was defined as the most advantageous method of Al foam cutting, as providing the best aluminium foam edges surface quality for welding.
Purpose: this paper was to determine the impact of the wide-gap welding, with increased root face... more Purpose: this paper was to determine the impact of the wide-gap welding, with increased root face gap, on structure and corrosion properties of the welded joints executed on duplex steel by one-side welding on ceramic backings.Design/methodology/approach: In the described work, experiments were conducted to welding tests for selected joints, visual examinations, non-destructive testing of welded joints, X-ray examinations, and metallographic testing of welded joints.Findings: As a result of the performed inspection, decreasing of the ferrite content with the increase of the root face gap (increase of welding heat input) was observed. The minimum measured ferrite content was not lower than 28 %, and the maximum value did not exceed 69% (the permissible range being from 25 to 70 %).Research limitations/implications: Further studies on the impact of the wide-gap welding, with increased root face gap, on structure and corrosion properties of the welded joints are required.Practical impl...
Purpose: test if the welding heat input exceeding the recommended values has negative impact on s... more Purpose: test if the welding heat input exceeding the recommended values has negative impact on strength properties and corrosion resistance of the executed welded joints as well as description of influence of the heat input of submerged arc welding (SAW) of duplex steel UNS S31803 (0.032%C, 23.17%Cr, 9.29%Ni, 3.48%Mo, 0.95%Mn, 0.7%Si, 0.16%N, 0.017P, 0.006%S, 0.11%Cu) on welded joints microstructure, particularly average values of ferrite volume fraction, mechanical properties, and corrosion resistance.Design/methodology/approach: analysis of welding heat input influence on mechanical properties, value of ferrite share, and corrosion of test joints has been done. Non-destructive and destructive testing, e. g. visual examinations, microstructure examination, corrosion resistance tests according to ASTM G48 Method A, HV5 hardness tests, impact and tensile test were carried out. For analysis of welding heat input influence on creation of welding imperfections, there were executed weld...
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Papers by Jerzy Nowacki