Pub Date : 1984-01-01DOI: 10.1179/030716984803274936
A. D. Brooker, J. Castle, J. Cohen, M. B. Waldron
AbstractArrest in the spreading of Au–18Ni braze alloy on a 12%Cr steel substrate has been investigated. Observations reported previously show that this alloy penetrates the oxide surface layer of the substrate at temperatures above its normal melting point to form a blister, but that spreading then ceases. It is shown here that the radius of the blister increases if the temperature of the substrate is increased until a stable radius is again achieved. Analyses show a correlation between the arrest in spreading and the composition of the spreading alloy, which suggests that interdiffusion of alloying elements between substrate and braze, leading to an elevation of melting point, is responsible for the behaviour.
{"title":"Influence of interdiffusion with substrate on spreading of molten Au–18Ni braze alloy","authors":"A. D. Brooker, J. Castle, J. Cohen, M. B. Waldron","doi":"10.1179/030716984803274936","DOIUrl":"https://doi.org/10.1179/030716984803274936","url":null,"abstract":"AbstractArrest in the spreading of Au–18Ni braze alloy on a 12%Cr steel substrate has been investigated. Observations reported previously show that this alloy penetrates the oxide surface layer of the substrate at temperatures above its normal melting point to form a blister, but that spreading then ceases. It is shown here that the radius of the blister increases if the temperature of the substrate is increased until a stable radius is again achieved. Analyses show a correlation between the arrest in spreading and the composition of the spreading alloy, which suggests that interdiffusion of alloying elements between substrate and braze, leading to an elevation of melting point, is responsible for the behaviour.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"28 1","pages":"66-70"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80790281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274404
G. F. Hancock
AbstractEnergy requirements are calculated for the manufacture of some non-ferrous metals, both from ore in the ground and from secondary sources. Lead, zinc, tin, magnesium, titanium, manganese, sodium, and nickel are treated at a lower level of detail, reflecting the relative paucity of information available on the energy required to produce these metals. Detailed breakdowns by fuel type are given for each metal considered.
{"title":"Energy requirements for manufacture of some non-ferrous metals","authors":"G. F. Hancock","doi":"10.1179/030716984803274404","DOIUrl":"https://doi.org/10.1179/030716984803274404","url":null,"abstract":"AbstractEnergy requirements are calculated for the manufacture of some non-ferrous metals, both from ore in the ground and from secondary sources. Lead, zinc, tin, magnesium, titanium, manganese, sodium, and nickel are treated at a lower level of detail, reflecting the relative paucity of information available on the energy required to produce these metals. Detailed breakdowns by fuel type are given for each metal considered.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"20 1","pages":"290-299"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75803081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274486
J. Mcgrath, M. Godden
{"title":"Application of instrumented Charpy test in evaluating toughness of heat-affected zones in linepipe welds","authors":"J. Mcgrath, M. Godden","doi":"10.1179/030716984803274486","DOIUrl":"https://doi.org/10.1179/030716984803274486","url":null,"abstract":"","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"92 1","pages":"515-518"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83495659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274729
M. Devgun, S. Garber, J. F. Hill
AbstractThe relationships between the magnetic permeability (in the form of digital voltmeter readings) and different mechanical properties of partially annealed lowcarbon mild steel sheet have been examined and the boundary conditions for the partial annealing defined. These relationships were statistically analysed and a method is proposed that may be used to monitor the ultimate tensile strength of the low-carbon mild steel sheet during continuous partial annealing. The proposed method is not applicable to the control of two other mechanical properties, namely, 0·2% proof stress and % total elongation; the reasons for this are stated.
{"title":"Mechanical and magnetic properties of partially annealed low-carbon mild steel sheet","authors":"M. Devgun, S. Garber, J. F. Hill","doi":"10.1179/030716984803274729","DOIUrl":"https://doi.org/10.1179/030716984803274729","url":null,"abstract":"AbstractThe relationships between the magnetic permeability (in the form of digital voltmeter readings) and different mechanical properties of partially annealed lowcarbon mild steel sheet have been examined and the boundary conditions for the partial annealing defined. These relationships were statistically analysed and a method is proposed that may be used to monitor the ultimate tensile strength of the low-carbon mild steel sheet during continuous partial annealing. The proposed method is not applicable to the control of two other mechanical properties, namely, 0·2% proof stress and % total elongation; the reasons for this are stated.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"1 1","pages":"369-377"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91234708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274314
D. Ford
AbstractThe properties principally affected by trace elements in Ni-based alloys are creep life and ductility. Results of experimental research have shown that the most detrimental element is Bi, which can reduce creep life by 20% at a contamination level of 0·2 ppm. This element is followed in the severity of its effect on these properties by Te, Se, Pb, and Ag, in that order. Gases in alloys affect cleanness and castability. Oxygen affects alloy cleanness by forming oxides, and increases the severity of metal-crucible reactions. Nitrogen is believed to affect the degree of microporosity formation in vacuum-cast Ni-based alloys. This element in Cobased alloys reduces ductility, but can also significantly increase tensile strength through strain aging. The paper concludes with a case study of Bi contamination in cast turbine rotor blades, which illustrates the importance of maintaining stringent trace element control.
{"title":"Importance of trace element control on mechanical and foundry properties of cast superalloys","authors":"D. Ford","doi":"10.1179/030716984803274314","DOIUrl":"https://doi.org/10.1179/030716984803274314","url":null,"abstract":"AbstractThe properties principally affected by trace elements in Ni-based alloys are creep life and ductility. Results of experimental research have shown that the most detrimental element is Bi, which can reduce creep life by 20% at a contamination level of 0·2 ppm. This element is followed in the severity of its effect on these properties by Te, Se, Pb, and Ag, in that order. Gases in alloys affect cleanness and castability. Oxygen affects alloy cleanness by forming oxides, and increases the severity of metal-crucible reactions. Nitrogen is believed to affect the degree of microporosity formation in vacuum-cast Ni-based alloys. This element in Cobased alloys reduces ductility, but can also significantly increase tensile strength through strain aging. The paper concludes with a case study of Bi contamination in cast turbine rotor blades, which illustrates the importance of maintaining stringent trace element control.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"70 1","pages":"438-445"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89228683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274918
R. F. Knight, W. Tyson, G. Sproule
AbstractAn investigation has been conducted into the suppression of temper embrittlement of 2·25Cr–1 steels by the addition of rare earth elements to scavenge phosphorus, which is the commonest embrittling impurity in these steels. Fracture surfaces were examined by scanning electron microscopy and Auger electron spectroscopy, and the compositions of inclusions determined by energydispersive spectroscopy and Auger electron spectroscopy. It was found that the shift in Charpy V-notch transition temperature after step cooling was indeed smaller in rare earth containing alloys. Hmrever, in the re-toughened condition, the Charpy V-notch upper-shelf energy was lower and the transition temperature higher in these alloys than in rare earth free alloys. This correlates with the increase in the volume fraction of inclusions caused by rare earth additions. The presence of rare earths, and occasionally phosphorus, in many of the inclusions was confirmed.
{"title":"Reduction of temper embrittlement of 2·25Cr–1Mo steels by rare earth additions","authors":"R. F. Knight, W. Tyson, G. Sproule","doi":"10.1179/030716984803274918","DOIUrl":"https://doi.org/10.1179/030716984803274918","url":null,"abstract":"AbstractAn investigation has been conducted into the suppression of temper embrittlement of 2·25Cr–1 steels by the addition of rare earth elements to scavenge phosphorus, which is the commonest embrittling impurity in these steels. Fracture surfaces were examined by scanning electron microscopy and Auger electron spectroscopy, and the compositions of inclusions determined by energydispersive spectroscopy and Auger electron spectroscopy. It was found that the shift in Charpy V-notch transition temperature after step cooling was indeed smaller in rare earth containing alloys. Hmrever, in the re-toughened condition, the Charpy V-notch upper-shelf energy was lower and the transition temperature higher in these alloys than in rare earth free alloys. This correlates with the increase in the volume fraction of inclusions caused by rare earth additions. The presence of rare earths, and occasionally phosphorus, in many of the inclusions was confirmed.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"117 1","pages":"273-279"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88241549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274512
T. Ráti, S. Somogyi, P. Tardy
AbstractA Quantimet 720 automatic image analyser has been used in a programme aiming to develop a new method for rating the cleanness of steels automatically. The method is based on mathematical pattern-recognition techniques, and combines the advantages of classical cleanness rating using picture charts with those of quantitative methods using automatic image analysers. The morphologies of the pictures containing inclusions were characterized by geometric quantities measured using the Quantimet. Classification of inclusion pictures was carried out on the basis of generalized ‘distance’ functions. The mathematical operations necessary for classification were performed by a PDP-1 1/23 computer linked to the Quantimet. Comparative tests on steel specimens and schematic inclusion pictures showed good agreement between the results obtained by automatic classification and those obtained by conventional visual assessment. The method seems to be suitable for the automatic classification of other microscopic images.
{"title":"Automatic cleanness rating of steels using image analyser and inclusion charts","authors":"T. Ráti, S. Somogyi, P. Tardy","doi":"10.1179/030716984803274512","DOIUrl":"https://doi.org/10.1179/030716984803274512","url":null,"abstract":"AbstractA Quantimet 720 automatic image analyser has been used in a programme aiming to develop a new method for rating the cleanness of steels automatically. The method is based on mathematical pattern-recognition techniques, and combines the advantages of classical cleanness rating using picture charts with those of quantitative methods using automatic image analysers. The morphologies of the pictures containing inclusions were characterized by geometric quantities measured using the Quantimet. Classification of inclusion pictures was carried out on the basis of generalized ‘distance’ functions. The mathematical operations necessary for classification were performed by a PDP-1 1/23 computer linked to the Quantimet. Comparative tests on steel specimens and schematic inclusion pictures showed good agreement between the results obtained by automatic classification and those obtained by conventional visual assessment. The method seems to be suitable for the automatic classification of other microscopic images.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"262 1","pages":"138-144"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75104363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803275089
J. Nelson, V. Tinnis, O. Vartiainen
AbstractStatistical analysis shows that energy costs on average are in the range of 20–35% of the production costs in the metal industry depending on the age of plant, working methods, and cost of energy, to give just a few examples. Since processing times can be considerably shortened and unnecessary operations eliminated, it is essential that reorganized routes and their consecutive sequences are carefully controlled. The concept of a coordinated production control can be shown to be a powerful tool for optimizing energy usage; a hierarchical approach in supervision and control enables efficient utilization of the informatics methodology. Energy consumption per unit of product is also dependent on the production capacity. At reduced capacity both heat and power consumption per unit of product tend to increase exponentially. The coordinated operation of the process units makes it possible to avoid idle running and thus reduce energy costs. As an additional saving potential, energy can be stored in interm...
{"title":"Energy conservation and energy management in the metals industry","authors":"J. Nelson, V. Tinnis, O. Vartiainen","doi":"10.1179/030716984803275089","DOIUrl":"https://doi.org/10.1179/030716984803275089","url":null,"abstract":"AbstractStatistical analysis shows that energy costs on average are in the range of 20–35% of the production costs in the metal industry depending on the age of plant, working methods, and cost of energy, to give just a few examples. Since processing times can be considerably shortened and unnecessary operations eliminated, it is essential that reorganized routes and their consecutive sequences are carefully controlled. The concept of a coordinated production control can be shown to be a powerful tool for optimizing energy usage; a hierarchical approach in supervision and control enables efficient utilization of the informatics methodology. Energy consumption per unit of product is also dependent on the production capacity. At reduced capacity both heat and power consumption per unit of product tend to increase exponentially. The coordinated operation of the process units makes it possible to avoid idle running and thus reduce energy costs. As an additional saving potential, energy can be stored in interm...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"49 1","pages":"341-346"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79965082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803275043
S. Saunders
AbstractGas-turbine blade materials are subject to attack by hot-salt corrosion processes. The mechanisms of both these reactions are briefly considered, with particular emphasis on the likely effects of impurities. It is shown that, while oxidation processes can be influenced by alloy-derived impurities, the hot-salt corrosion reaction is significantly affected only by impurities in the environment. Finally, the inhibition of oxidation and hot-salt corrosion by the deliberate addition of certain compounds to the environment is discussed.
{"title":"Effects of trace elements and environmental impurities on oxidation and hot-corrosion characteristics of superalloys","authors":"S. Saunders","doi":"10.1179/030716984803275043","DOIUrl":"https://doi.org/10.1179/030716984803275043","url":null,"abstract":"AbstractGas-turbine blade materials are subject to attack by hot-salt corrosion processes. The mechanisms of both these reactions are briefly considered, with particular emphasis on the likely effects of impurities. It is shown that, while oxidation processes can be influenced by alloy-derived impurities, the hot-salt corrosion reaction is significantly affected only by impurities in the environment. Finally, the inhibition of oxidation and hot-salt corrosion by the deliberate addition of certain compounds to the environment is discussed.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"48 1","pages":"465-473"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76253749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274305
T. Endo, T. Sakon
AbstractSeveral criteria have been proposed for the fracture caused by creep-fatigue interaction and many studies are still being made to verify the validity of these criteria. Most of the studies, however, are based on data obtained by short-time tests. A simple high-temperature low-cycle fatigue testing machine for long-time creep-fatigue tests has been developed and experiments on two kinds of Cr-Mo-V steel forgings and 304 stainless steel plate carried out. The experimental results indicate: (1) the data obtained by long-hold time tests deviate considerably from the linear damage fraction rule; (2) creep-rupture ductility seems to be one of the important factors affecting creep-fatigue life after long times; and (3) in the case of materials whose creep-rupture ductility shows a marked variation with time, Manson's ∆ecp—∆Ncp diagram may not become a single line.
{"title":"Creep-fatigue life prediction using simple high-temperature low-cycle fatigue testing machines","authors":"T. Endo, T. Sakon","doi":"10.1179/030716984803274305","DOIUrl":"https://doi.org/10.1179/030716984803274305","url":null,"abstract":"AbstractSeveral criteria have been proposed for the fracture caused by creep-fatigue interaction and many studies are still being made to verify the validity of these criteria. Most of the studies, however, are based on data obtained by short-time tests. A simple high-temperature low-cycle fatigue testing machine for long-time creep-fatigue tests has been developed and experiments on two kinds of Cr-Mo-V steel forgings and 304 stainless steel plate carried out. The experimental results indicate: (1) the data obtained by long-hold time tests deviate considerably from the linear damage fraction rule; (2) creep-rupture ductility seems to be one of the important factors affecting creep-fatigue life after long times; and (3) in the case of materials whose creep-rupture ductility shows a marked variation with time, Manson's ∆ecp—∆Ncp diagram may not become a single line.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"10 1","pages":"489-496"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90453558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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