Perguntas de Revisão sobre Aços: Composição, Propriedades e Classificações AISI-SAE

Chapter 6 Review Questions 15 What is plaincarbon steel 16 What is considered a lowcarbon steel Mediumcarbon Highcarbon 17 What properties account for the highvolume use of mediumcarbon steels 18 Why should plaincarbon steels be given first consideration for applications requiring steel 19 What are some of the common alloy elements added to steel 20 For what different reasons might alloying elements be added to steel 21 What are some of the alloy elements that tend to form stable carbides within a steel 22 While strength and hardness are dependent on the level of carbon what is primary role of the alloy additions in a heattreated steel 23 What alloys are particularly effective in increasing the hardenability of steel 24 What is the basis of the AISISAE classification system ie strength structure chemistry 25 What is the significance of the last two digits in a typical fourdigit AISISAE steel designation 26 How are letters incorporated into the AISISAE designation system for steel and what do some of the more common ones mean 27 What is an Hgrade steel and when should it be considered in a material specification 28 Why should the proposed fabrication processes enter into the considerations when selecting a steel 29 How are the final properties usually obtained in the constructional alloy steels In the conventional highstrength steels 30 How are the highstrength steels typically specified 31 What are microalloyed steels 32 What are some of the potential benefits that might be obtained through the use of microalloyed steels 33 What is the primary attraction of the bakehardenable steels 34 What are advanced highstrength steels AHSS 35 What are the two phases that are present in dualphase steels 36 What is the transformation that occurs during the deformation of the transformationinduced plasticity TRIP steels 37 What are some other types of advanced highstrength steels AHSS 38 What is press hardening 39 What nomenclature has been applied to identify the advancedhighstrength steels 40 Describe the role of steel in the automotive industry during the past 50 years What is the projection for the near future 41 What is the role of chipbreakers in freemachining steels 42 What are some of the various alloy additions that have been used to improve the machinability of steels 43 What are some of the compromises associated with the use of freemachining steels 44 What factors might be used to justify the added expense of precoated steel sheet 45 What are some of the coating materials that have been applied to precoated steel sheet 46 What are soft magnetic materials 47 Why have the amorphous metals attracted attention as potential materials for magnetic applications P14 CHAPTER 6 Problems 48 What are maraging steels and for what conditions might they be required 49 What are the typical elevated temperature limits of plain carbon and alloy steels 50 What feature is responsible for the observed corrosion resistance of stainless steels 51 What are the three primary families of stainless steels based on microstructures 52 Why should ferritic stainless steels be given first consideration when selecting a stainless steel 53 Which of the major types of stainless steel is likely to contain significant amounts of carbon Why 54 Under what conditions might a martensitic stainless steel rust when exposed to a hostile environment 55 What are some of the unique properties of austenitic stainless steels 56 How can an austenitic stainless steel be easily identified 57 What is the dominant mechanism providing strength for each of the three primary types of stainless steels 58 What two microstructures are present in a duplex stainless steel 59 What is sensitization of a stainless steel and what are the several methods to minimize or prevent it 60 What problem is associated with the presence of sigma phase in a stainless steel 61 What is a tool steel 62 How does the AISISAE designation system for tool steels differ from that of plaincarbon and alloy steels 63 What is the least expensive variety of tool steel 64 For what types of applications might an oil or airhardenable tool steel be attractive 65 What alloying elements are used to produce the highspeed and hotwork tool steels 66 What assets can be provided by the hotisostaticpressed powder metallurgy tool steels 67 What are the three primary chemical elements in a cast iron 68 What is a generic description of the structure of cast irons 69 Describe the microstructure of gray cast iron 70 Which of the structural units is generally altered to increase the strength of a gray cast iron 71 What are some of the attractive engineering properties of gray cast iron 72 What are some of the key limitations to the engineering use of gray cast iron 73 What is the dominant mechanical property of white cast iron 74 How is malleable cast iron produced 75 What structural feature is responsible for the increased ductility and fracture resistance of malleable cast iron 76 What is unique about the shape or form of graphite in ductile cast iron and what is required to produce it 77 What is the purpose of inoculation when making ductile cast iron Of nodulizing 78 What is fading Why should ductile iron be solidified immediately following nodulizing 79 What requirements of ductile iron manufacture are responsible for its increased cost over materials such as gray cast iron 80 What are some of the attractive features of austempered ductile cast iron 81 Compacted graphite iron has a structure and properties intermediate to what two other types of cast irons 82 What are some of the reasons that alloy additions are made to cast irons that will be used in their ascast condition 83 What properties are enhanced in the highalloy cast irons 84 When should cast steel be used instead of a cast iron 85 In what ways might a cast steel be more difficult to process than a cast iron 86 Why are standard geometry test bars often cast along with manufactured products