Search Results for controlled-toughness alloy

This article discusses the effect of alloying on high-strength low-alloy (HSLA) steels. It explains where HSLA steels fit in the continuum of commercial steels and describes the six general categories into which they are divided. It provides composition data for standard types or grades of HSLA steel along with information on available mill forms, key characteristics, and intended uses. The article explains how small amounts of alloying elements, particularly vanadium, niobium, and titanium, control not only the properties of HSLA steels, but also their manufacturability.

This chapter provides information and data on the fatigue and fracture properties of steel, aluminum, and titanium alloys. It explains how microstructure, grain size, inclusions, and other factors affect the fracture toughness and fatigue life of these materials and the extent to which they can be optimized. It also discusses the effect of metalworking and heat treatment, the influence of loading and operating conditions, and factors such as corrosion damage that can accelerate crack growth rates.

This chapter reviews the concepts of fracture mechanics and their application to materials evaluation and the design of cryogenic structures. Emphasis is placed on an explanation of technology, a review of fracture mechanics testing methods, and a discussion on the many factors contributing to the fracture behavior of materials at cryogenic temperatures. Three approaches of elastic-plastic fracture mechanics are covered, namely the crack opening displacement, the J-integral, and the R-curve methods. The chapter also discusses the influence of thermal and metallurgical effects on toughness at low temperatures.

This chapter describes the classification of steels and the various compositional categories of commercial steel products. It explains how different alloying elements affect the properties of carbon and low-alloys steels and discusses strength, toughness, and corrosion resistance and how to improve them.

This article discusses the role of alloying in the production and use of carbon and low-alloy steels. It explains how steels are defined and selected based on alloy content and provides composition and property data for a wide range of designations and grades. It describes the effect of alloying on structure and composition and explains how alloy content can be controlled to optimize properties and behaviors such as ductility, strength, toughness, fatigue and fracture resistance, and resistance to corrosion, wear, and high-temperature creep. It also examines the effect of alloying on processing characteristics such as hardenability, formability, weldability, machinability, and temper embrittlement. In addition, the article provides an extensive amount of engineering data with relevance in materials selection.

This chapter examines the process, structure, and property relationships in titanium alloys. It provides information on microstructures and strengthening mechanisms, the role of alloy and interstitial elements, and the effect of composition, processing, and surface treatments on tensile and yield strength, fracture toughness, hardness, ductility, and creep and fatigue behaviors. The chapter covers wrought, cast, and powder metal titanium alloys and contains an extensive amount of property data.

This chapter discusses the equipment and processes used to convert titanium billet and bar into useful shapes or more refined product forms. These secondary working operations include open-die, closed-die, hot-die and isothermal forging as well as ring rolling and extruding. The chapter describes each method in detail and how it affects the microstructure and mechanical properties of various titanium alloys. It also discusses the propensity of titanium to react with oxygen and hydrogen when heated and explains how to mitigate the effects.

Tool steels are specialty steels, produced in relatively low volumes, optimized for applications requiring precise combinations of wear resistance, toughness, and hot hardness. This chapter describes the AISI classification system by which tool steels are defined. It discusses primary types, including high-speed and shock-resisting steels, and their associated subtype groups (W, L, S, O, A, D, H, M, and T series). It also discusses the types of carbides found in tool steels and their influence on mechanical properties. The chapter concludes with a discussion on heat treatment effects unique to tool steels, including two-phase effects, austenite stabilization, and the conditioning of retained austenite.

The water-hardening steels are either essentially plain carbon steels or very low-alloy carbon steels. As a result, the water-hardening tool steels are the least expensive of tool steels and require strict control of processing and heat treatment to achieve good properties and performance. This chapter provides an overview of general processing and performance considerations of water-hardening tool steels. It describes the microstructural characteristics and hardenability of water-hardening tool steels. The chapter discusses the processes involved in the hardening and tempering of water-hardening tool steels.

This chapter presents an overview of some of the major causes of tool and die failures. The chapter describes fracture and fracture toughness of tool steels, and the influence of factors such as steel quality and primary processing, mechanical design, heat treatment, grinding and finishing, and distortion and dimensional change.

Stainless steel base metals and the welding filler metals used with them are chosen on the basis of suitable corrosion resistance for the intended application. This article describes several constitution diagrams that that have been developed to predict microstructures and properties. This is followed by discussions of weldability, cracking, and the engineering properties of stainless steel welds, namely martensitic stainless steels, ferritic stainless steel welds, austenitic stainless steels, and duplex stainless steels.

Fracture mechanics is a well-developed quantitative approach to the study of failures. This chapter discusses fracture toughness and fracture mechanics, linear-elastic fracture mechanics, and modes of loading. The discussion also covers plane strain and stress and crack growth kinetics. The chapter presents a case history that illustrates the use of fracture mechanics in failure analysis. An appendix provides a more detailed discussion of fracture mechanics concepts.

This article reviews the fundamental and specific factors that control the properties of steel weldments in both the weld metal and heat-affected zone (HAZ). The influence of welding processes, welding consumables, and welding parameters on the weldment properties is emphasized. The service properties of weldments in corrosive environments are considered and subjected to cyclic loading. The article summarizes the effects of major alloying elements in carbon and low-alloy steels on HAZ microstructure and toughness. It discusses the processes involved in controlling toughness in the HAZ and the selection of the proper filler metal. The article provides a comparison between single-pass and multipass welding and describes the effect of welding procedures on weldment properties and the effects of residual stresses on the service behavior of welded structures. It also describes the fatigue strength and fracture toughness of welded structures. The article reviews various types of corrosion of weldments.

Titanium alloys are classified according to the amount of alpha and beta phase material retained in their structures at room temperature. This chapter discusses the metallurgy, composition, processing, and properties of titanium and its alloys. It provides information on melting, forging, casting, heat treating, and secondary fabrication. It also discusses the advantages and disadvantages of titanium and its alloys in various applications.

This chapter is a brief account of the composition, microstructures, heat treatment, deformation mechanisms, mechanical properties, formability, and special attributes of austenitic stainless steels.

Austenitic stainless steels are iron-base alloys containing more than 50% Fe, 15 to 26% Cr, and less than 45% Ni. This chapter provides a discussion on the types, compositions, microstructures, processing, deformation mechanism, mechanical properties, formability, and special attributes of austenitic stainless steels.

This chapter discusses the various methods used to join titanium alloy assemblies, focusing on welding processes and procedures. It explains how welding alters the structure and properties of titanium and how it is influenced by composition, surface qualities, and other factors. It describes several welding processes, including arc welding, resistance welding, and friction stir welding, and addresses related issues such as welding defects, quality control, and stress relieving. The chapter also covers mechanical fastening techniques along with adhesive bonding and brazing.

Most quenched steels are tempered because the toughness of as-quenched steels is generally very poor. The tempering operation sacrifices strength for improvements in ductility and toughness. This chapter discusses the tempering process, the challenge of tempered martensite embrittlement, and the effect of wt% carbon on toughness. It also explains how alloying elements improve the hardenability and tempering response of plain carbon steels.

This chapter discusses the factors that govern the mechanical properties of titanium, beginning with the morphology of the alpha phase. It explains that the shape of the alpha phase has a significant effect on many properties, including hardness, tensile strength, toughness, and ductility as well as creep, fatigue strength, and fatigue crack growth rate. It also discusses the influence of other titanium phases and the properties of titanium-based intermetallic compounds, metal-matrix composites, and shape-memory alloys.