Metals technology最新文献

{"title":"Comparison of two methods of cold work to increase strength of hot-rolled reinforcing bar","authors":"L. N. Pussegoda","doi":"10.1179/030716984803274891","DOIUrl":"https://doi.org/10.1179/030716984803274891","url":null,"abstract":"","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"55 1","pages":"208-210"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86507286","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}

{"title":"Summary: Effects of minor elements on weld cracking in superalloys","authors":"M. Gittos, M. Scott","doi":"10.1179/030716984803274972","DOIUrl":"https://doi.org/10.1179/030716984803274972","url":null,"abstract":"There are several distinct types of cracking which can occur during the fusion welding of superalloys, and they can all occur at high temperature. The cracking may occur in the weld metal or the heat-affected zone (HAZ), either during the making of the weld or during subsequent post-weld heat treatment. The latter applies only to precipitationhardened alloys, and has been described as strain-age cracking, but heat-treatment cracking is the preferred term. Solidification cracking occurs in the weld metal during the freezing of the weld pool and is usually referred to as being super-solidus. Liquation cracking occurs either in the HAZ or in previously deposited weld metal, reheated by an adjacent subsequent pass; it is associated with microsegregation. Ductility-dip cracking occurs in the HAZ, in weld metal, or in weld metal reheated by subsequent passes, and the same is true of heat-treatment cracking. Superalloys can be based on Fe, Ni, or Co, but most of the reported information relates to Ni-based alloys and very little to Co-based alloys. Nearly all of it deals with contents of minor elements above those that would normally be regarded as trace levels. The information available in the literature contains numerous apparent contradictions concerning the effects of elements on both individual crack mechanisms and different types of cracking. The influence of the various elements on weld cracking is discussed by grouping together the reported effects of each element on the various alloys and mechanisms which have been investigated. The behaviour of C provides an example of the confusing results that have been reported. Although one leading authority states that C has no effect on the weldability of Ni-Cr alloys, others have found that it promotes HAZ liquation, that it should be increased to stop HAZ liquation, and at low levels that it either aggravates or ameliorates post-weld heat-treatment cracking. There is general agreement on the detrimental effects of S, P, Pb, Sn, and Zr on high-temperature cracking resistance, and that high levels of Ti +Al promote postweld heat-treatment cracking. However, the effects of C, Si, Mg, and La are variable, and elements such as B have been shown to act in opposite senses for different crack mechanisms. Nb and Mn are generally accepted as having beneficial influences on weld cracking, although both have been demonstrated by microanalysis techniques to show an association with liquated (but not necessarily cracked) grain boundaries. In part, these contradictions can perhaps be explained by the existence of critical ranges within which a given element is harmful. This behaviour is perhaps best known and documented for AI alloys, where the effect of a given element on solidification cracking passes through a maximum at some given concentration. There is also the possibility of interaction between elements, minor and/or major, which may well influence the effect of any given element; this is particularly likely t","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"25 1","pages":"453-453"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76737227","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}

{"title":"Conservation of energy and materials by recycling complex alloys","authors":"G. Horn","doi":"10.1179/030716984803274413","DOIUrl":"https://doi.org/10.1179/030716984803274413","url":null,"abstract":"AbstractTechniques for the recycling of complex alloys containing nickel, chromium, cobalt, molybdenum, tungsten, and titanium, in both solid and particulate form, are discussed. Material processed in this way has been accepted as sufficiently pure for direct charging into vacuum melting furnaces. Typical energy and cost savings that can be achieved by recycling complex alloys are presented.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"22 1","pages":"347-349"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89672781","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}

{"title":"Formability of soft-magnetic Ni–Fe alloy sheet","authors":"Y. Yoo, D. N. Lee","doi":"10.1179/030716984803275098","DOIUrl":"https://doi.org/10.1179/030716984803275098","url":null,"abstract":"AbstractThe formabilities of Ni–Fe alloy sheets were evaluated by measuring their tensile strengths, yield strengths, elongations to failure, strain-hardening exponents, and plastic-strain anisotropy ratios R at various directions to the rolling direction and for various textures. The higher-nickel alloy (75–82Ni–12–18Fe–Mo–Cr–Cu/Mn) sheets had higher tensile strengths, elongations, and strain-hardening exponents than did those of the lower-nickel alloy (47Ni–53Fe). The strain levels of the forming-limit curves were higher for the higher-nickel alloys, as, generally, were the R-values obtained (0·67−0·93, compared with 0·38−1·1 for the lower-nickel alloys) and the R-value fluctuations. The R-value maxima at 45−67° to the rolling direction for the higher-nickel alloy sheets and the minimum at 45° for the lower-nickel alloy sheets are attributed to the competitive contributions of the {358}〈835〉 texture, which gives a maximum at 45°, and the {001}〈100〉 texture, which produces a minimum at 45°. Thus, the hig...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"255 1","pages":"91-98"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73120941","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}

{"title":"Cold roll and indent vvelding of some metals","authors":"R. Pendrous, A. Bramley, G. Pollard","doi":"10.1179/030716984803274459","DOIUrl":"https://doi.org/10.1179/030716984803274459","url":null,"abstract":"AbstractThe cold pressure welding of copper, brass, aluminium, and stainless steel has been investigated using thin-layer metal sandwiches produced by roll bonding and plane-strain indent welding. Shear tests were carried out to assess the level of bonding and scanning electron microscopy used to examine peeled surfaces from bonded specimens. Welding was found to be initiated by the formation of transverse cracks in the surface layers of the mating surfaces. These cracks coincide on both surfaces and are widened during deformation allowing extrusion of the base material through the cracks until a weld is formed. Extension of the surfaces is necessary for welding and the dependence of threshold deformation on the welding geometry is associated with the different surface behaviour. No recrystallization at interfacial regions was observed.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"214 1","pages":"280-289"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73783131","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}

{"title":"Low-carbon Mn-Ni-Nb steel: Part 1 Development for pipeline applications using relaxed rolling conditions","authors":"F. Heisterkamp, K. Hulka","doi":"10.1179/030716984803274495","DOIUrl":"https://doi.org/10.1179/030716984803274495","url":null,"abstract":"AbstractA new microalloy steel has been developed which relies on 0·5%Ni to depress the austenite-ferrite transformation temperature, and on 0·10–0·17%Nb to give large amounts of Nb(C, N) in the austenite during hot processing to enhance grain refinement. It is found that a significantly higher rolling temperature can be used to achieve the properties of conventional microalloy steels, with the implied benefits of relaxed rolling schedules, reduced anisotropy, and the elimination of fracture separations. Various combinations of soaking temperature, thermomechanical processing, plate thickness, and finish rolling temperature have been investigated in full-scale industrial trials on 150 t heats conducted by seven European steel companies. Strength levels of X65 to X75 (yield strengths of 450 to 515 MN m−2) can be obtained, along with excellent toughness. Measurements of dissolved Nb and electron microscopy have indicated that up to 95% of the Nb can be precipitated out in the austenite in a wide range of pa...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"25 1","pages":"535-544"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89755104","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}

{"title":"Role of niobium in a dual-phase steel","authors":"J. Guimarães, K. Chawla, P. R. Rios, J. M. Rigsbee","doi":"10.1179/030716984803275151","DOIUrl":"https://doi.org/10.1179/030716984803275151","url":null,"abstract":"AbstractTwo hot-rolled high-strength, low-alloy steels, one microalloyed with niobium, were intercritically annealed at 740°C for 10 min and cooled to produce a dual-phase microstructure. Although both steels showed tensile properties typical of dual-phase microstructures, only the niobium-microalloyed steel could match the mechanical characteristics of a typical commercial dual-phase steel. The role of the niobium would appear to be to provide a suitable level of strength in the initial, as-rolled state of the steel, since the properties in the dual-phase state were found to be a function of the initial state of the steel. A normalizing treatment resulted in grain refinement in both steels, but transmission electron microscopy observations showed that in the niobium-containing steel this was counterbalanced by an increase in Nb(C, N) precipitate size. The normalizing treatment thus equalized the mechanical properties of the initial state of the two steels, leading to similar dual-phase properties in both...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"64 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91465896","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}

{"title":"Creep-rupture properties and microstructure of AISI type 316L submerged arc weld metals","authors":"R. Thomas, R. Nicholson, R. Farrar","doi":"10.1179/030716984803275133","DOIUrl":"https://doi.org/10.1179/030716984803275133","url":null,"abstract":"AbstractA series of submerged-arc butt welds has been produced in AISI type 316L steel plate using different commercial consumables. These consumables produce only small changes in the as-deposited analyses, but significant differences in the δ-ferrite content. The stress rupture, minimum creep rate, and creep ductility of these welds have been measured at 600°C and stress levels between 170 and 240 M N m−2. The creep-rupture values were comparable with those for manual metal arc welds, and fall within the lower limits of the scatter observed for wrought materials. The proportion of δ-ferrite was found to have little influence on creep ductility, with the exception of the weld containing 20% which consistently showed lower ductility. The nature and extent of the δ-ferrite transformation on aging at 600°C varied between the weld metals, but generally followed the sequence δ-ferrite → M23 C6 → intermetallic σ- and χ-phases.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"62 1","pages":"61-65"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75971451","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}

{"title":"Effect of small amounts of nitrogen and silicon on microstructure and properties of MAR-M002 nickel-base superalloy","authors":"G. Durber, S. Osgerby, P. Quested","doi":"10.1179/030716984803274251","DOIUrl":"https://doi.org/10.1179/030716984803274251","url":null,"abstract":"AbstractThe microstructure and the tensile and stress-rupture properties of the nickel-base superalloy M A R-M002 have been studied using material of normal commercial composition and three melts with additions of 0·0024 and 0·0050%N and of 0·16%Si. Increasing the nitrogen content resulted in a change in carbide morphology, from ‘Chinese script’ to a blocky form, and to increased microporosity. Interference-film microscopy revealed characteristic centres in some of the blocky carbides that had high Ti contents consistent with carbide nucleation on Ti(C, N) particles formed in the melt. The increased nitrogen content was associated with a significant decrease in the rupture life at 760°C and 695 MN m−2, and a change in the fracture morphology. In the Si-doped alloy, which contained little microporosity, there were increased amounts of a phase rich in Ni–Hf (probably Ni5Hf) that also contained Si, but there was only a slight decrease in stress-rupture properties.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"106 1","pages":"129-137"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79552109","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}

{"title":"Optimization of high-temperature compression of as-cast Al–Cu eutectic alloy","authors":"G. A. Nasset, A. El-Ashram, M. Suéry","doi":"10.1179/030716984803274468","DOIUrl":"https://doi.org/10.1179/030716984803274468","url":null,"abstract":"AbstractThe superplastic characteristics achieved after compressive predeformation at high temperature of as-cast Al–Cu eutectic alloy have been studied as function of the predeformation speed Vp. The stress–strain-rate curve was found to be shifted towards higher strain rates as the predeformation speed becomes higher, so that the maximum superplastic strain rate is found to increase with Vp’ with however a tendency for stabilization at high Vp. This phenomenon can be explained by the combined effect of homogeneity of transformation of the initial lamellar structure in the compressed specimen and of the size of the equiaxed structure developed in the transformed regions. The influence of Vp on the subsequent superplastic characteristics of the material allows optimization of that predeformation speed to achieve a given total strain under conditions of minimum energy and/or time of deformation. The effect of the cooling rate of the as-cast material was also examined and is discussed in terms of superplast...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"1 1","pages":"196-200"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72683735","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}