This article discusses the main materials and water chemistry characteristics of the primary and secondary water circuits of a pressurized water reactor (PWR). It reviews the corrosion issues of PWR materials and the influence of corrosion and fouling on primary and secondary circuit radiation fields. The article explains the primary side intergranular stress corrosion cracking (IGSCC) in different materials, namely, nickel-base alloys, high-strength nickel-base alloys, low-strength austenitic stainless steels, and high-strength stainless steels. The secondary side corrosion in steam generator including denting, pitting, intergranular attack and IGSCC is also discussed. The article examines laboratory studies that have resulted in models and computer codes for evaluating and predicting intergranular corrosion, and considers the remedial actions for preventing or arresting intergranular corrosion. It concludes with information on the external bolting corrosion in nuclear power reactors.

Fabrication of wrought stainless steels requires use of greater power, more frequent repair or replacement of processing equipment, and application of procedures to minimize or correct surface contamination because of its greater strength, hardness, ductility, work hardenability and corrosion resistance. This article provides a detailed account of such difficulties encountered in the fabrication of wrought stainless steel by forming, forging, cold working, machining, heat treating, and joining processes. Stainless steels are subjected to various heat treatments such as annealing, hardening, and stress relieving. Stainless steels are commonly joined by welding, brazing, and soldering. The article lists the procedures and precautions that should be instituted during welding to ensure optimum corrosion resistance and mechanical properties in the completed assembly.

Cryogenic temperatures cause many structural alloys to become brittle, which is an unacceptable condition in most structural applications and is rectified by optimizing the weld composition. Although nonmatching weld compositions are most appropriate, differences between the welds and parent material in terms of thermal contraction, corrosion, and other factors must be considered. This article discusses these differences and describes the effect of these factors on the choice of the weld filler metal. It also provides a detailed discussion on the effects of cryogenic services on mechanical properties of the parent metal.

Stainless steels are highly alloyed materials in comparison to most other popular powder metallurgy (PM) materials, such as low-alloy steels, copper alloys, and aluminum alloys. This article provides an overview of the history of PM stainless steels.

The warm and hot working of metals provide the ability to shape important materials into component shapes that are useful in a variety of applications requiring strength, toughness, and ductility. This article focuses on a variety of metals that can be hot or warm worked, and describes the characteristics and processing considerations of each metal. It discusses forging because it is a versatile metalworking process and performed at cold, warm, and hot working temperatures. The article also presents the applications of steels, stainless steels, aluminum alloys, titanium alloys, superalloys, and copper alloys.

Stainless steels are primarily alloys of iron and chromium. They are grouped into five families, primarily based on their microstructure: ferritic, austenitic, martensitic, duplex, and precipitation hardening. Three out of the five families of stainless steels, namely, austenitic, ferritic, and martensitic, are well suited for manufacture via conventional powder metallurgy (PM) processes. This article presents the iron-chromium partial phase diagram to illustrate the changes in the temperature range when pure iron is alloyed with chromium. It describes AISI and UNS numbering systems, which are used as an identification system for stainless steels. The article tabulates the material designations of stainless steels in accordance with the Metal Powder Industries Federation. It also details the characteristics and chemical composition of wrought and PM stainless steels.

This article reviews the influence of local strains and corrosion fatigue on the initiation of fatigue cracks in duplex stainless steels. It provides useful information on fatigue crack growth, fatigue strength, and fracture toughness of duplex stainless steels. The article discusses the fatigue and fracture behavior of duplex stainless steels during stress-corrosion cracking. It details the elevated-temperature properties of duplex stainless steels, such as creep-fatigue behavior and thermal cycling properties.

Characteristics of stainless steel that affect its formability include yield strength, tensile strength, and ductility, in addition to the effect of work hardening on these properties. This article discusses the forming process of stainless steel, heat-resistant alloys and refractory metals, detailing the major aspects of forming, including formability, lubrication, and forming methods and tools. The effect of factors such as alloy condition, cold reduction, forming direction (in the case of heat-resistant alloys) and temperature (in the case of refractory metals) on formability is also discussed.

Stainless steels are widely used at elevated temperatures when carbon and low-alloy steels do not provide adequate corrosion resistance and/or sufficient strength at these temperatures. This article deals with the wrought stainless steels used for high temperature applications. It gives some typical compositions of wrought heat-resistant stainless steels, which are grouped into ferritic, martensitic, austenitic, and precipitation-hardening (PH) grades. Quenched and tempered martensitic stainless steels are essentially martensitic and harden when air cooled from the austenitizing temperature. These alloys offer good combinations of mechanical properties. The article focuses on mechanical property considerations and corrosion resistance considerations of stainless steels. The corrosion and oxidation resistance of wrought stainless steels is similar to that of cast stainless steels with comparable compositions.

Martensitic stainless steels are the least corrosion-resistant of all stainless alloys. The traditional martensitic stainless steels are iron/chromium/carbon alloys, sometimes with a small amount of nickel and/or molybdenum. This article provides an overview on the influences of the various possible alloying elements on the key properties of martensitic stainless steels. It describes the various preparation processes, namely, atmosphere selection, cleaning, and preheating, prior to heat treatment for these steels. Common heat treatment methods include annealing, hardening, tempering, and stress relieving. The article lists the compositions of casting alloys and also describes the effect of tempering temperature on the hardness, strength, ductility, and toughness properties of the alloys.

Steels are among the most versatile materials in modifying their microstructure and properties by heat treatment. This article outlines the basic concepts of physical metallurgy relating to the heat treatment of steel. It considers the phases and microstructures of steel together with the transformations observed and critical temperatures during heat treatment. Additionally, the different types of steels, heat treatments, and their purposes are also discussed.

Stainless steel powder metallurgy (P/M) parts represent an important and growing segment of the P/M industry. This article describes the processing, properties, and composition of medium-density and high-density P/M stainless steels. Medium-density materials are processed by pressing and sintering prealloyed stainless powders. High-density materials are produced by hot isostatic pressing, cold isostatic pressing followed by extrusion, or metal injection molding. The comparison of mechanical properties of these P/M stainless steels is represented graphically. The article contains a table that lists the effect of iron, carbon, nitrogen, oxygen, and density on the corrosion resistance of the sintered austenitic stainless steels.

This article describes the fracture toughness behavior of austenitic stainless steels and their welds at ambient, elevated, and cryogenic temperatures. Minimum expected toughness values are provided for use in fracture mechanics evaluations. The article explains the effect of crack orientation, strain rate, thermal aging, and neutron irradiation on base metal and weld toughness. It discusses the effect of cold-work-induced strengthening on fracture toughness. The article examines the fracture toughness behavior of aged base metal and welding-induced heat-affected zones. It concludes with a discussion on the Charpy energy correlations for aged stainless steels.

This article describes the sintering behavior of austenitic, ferritic, and martensitic stainless steels. It presents different sintering schedules that are selected by Metal Powder Industries Federation (MPIF). The article provides information on the equipment and atmospheres used for sintering and the steps involved in the process. It discusses the factors that influence the dimensional changes in sintering, namely, powder-related, compaction-related, and sintering-related factors.

Stainless steels are iron-base alloys containing minimum of approximately 11% Cr, and owing to its excellent corrosion resistance, are used for wide range of applications. These applications include nuclear reactor vessels, heat exchangers, oil industry tubular, chemical processing components, pulp and paper industries, furnace parts, and boilers used in fossil fuel electric power plants. The article provides a brief introduction on corrosion resistance of wrought stainless steel and its designations. It lists the chemical composition and describes the physical and mechanical properties of five major stainless steel families, of which four are based on the crystallographic structure of the alloys, including martensitic, ferritic, austenitic, or duplex. The fifth is precipitation-hardenable alloys, based on the type of heat treatment used. The article further discusses the factors in the selection of stainless steel, namely corrosion resistance, fabrication characteristics, product forms, thermally induced embrittlement, mechanical properties in specific temperature ranges, and product cost.

This article describes the factors influencing the room-temperature and elevated-temperature mechanical properties of powder metallurgy (PM) stainless steels. It contains tables that list the mechanical property specifications of the Metal Powder Industries Federation (MPIF) Standard 35.

Repair and maintenance of parts and components is carried out as a logical procedure that ensures the production of a usable and safe component or it can be approached haphazardly. This article describes the requirements and repair techniques of arc and oxyfuel welding processes to repair weld defects and structural failures. It further discusses the preliminary assessment and base-metal preparation involved in weld repair. Furthermore, the article provides information on the general repair guidelines that are followed to ensure successful weld repairs of both ferrous (carbon steels, cast irons, and stainless steels) and nonferrous (titanium) base metals.

This article summarizes the key mechanical characteristics of various types of stainless steel, including ferritic, austenitic, martensitic, precipitation hardening, and duplex steels. Particular emphasis is on fracture properties and corrosion fatigue. The article tabulates typical room-temperature mechanical properties and fatigue endurance limits of stainless steels. Stainless steels are susceptible to embrittlement during thermal treatment or elevated-temperature service. The article discusses embrittlement in terms of sensitization, 475 deg C embrittlement, and sigma-phase embrittlement. It also describes the effect of environment on fatigue crack growth rate.

This article discusses the composition, characteristics, and properties of the five groups of wrought stainless steels: martensitic stainless steels, ferritic stainless steels, austenitic stainless steels, duplex stainless steels, and precipitation-hardening stainless steels. The selection of stainless steels may be based on corrosion resistance, fabrication characteristics, availability, mechanical properties in specific temperature ranges and product cost. The fabrication characteristics of stainless steels include formability, forgeability, machinability, and weldability. The product forms of wrought stainless steels are plate, sheet, strip, foil, bar, wire, semifinished products, pipes, tubes, and tubing. The article describes tensile properties, elevated-temperature properties, subzero-temperature properties, physical properties, corrosion properties, and fatigue strength of stainless steels. It characterizes the experience of a few industrial sectors according to the corrosion problems most frequently encountered and suggests appropriate grade selections. Corrosion testing, surface finishing, mill finishes, and interim surface protection of stainless steels are also discussed.

Hydrogen damage is a form of environmentally assisted failure that results from the combined action of hydrogen and residual or applied tensile stress. This article classifies the various forms of hydrogen damage and summarizes the theories that seek to explain these types of degradation. It reviews hydrogen degradation in specific ferrous and nonferrous alloys, namely, iron-base alloys, nickel alloys, aluminum alloys, copper alloys, titanium alloys, zirconium alloys, and vanadium, niobium, tantalum, and their alloys. An outline of hydrogen damage in intermetallic compounds is also provided.