Search Results for Preventative maintenance

This chapter discusses the maintenance needs of major components in induction heat-treating systems, including power supplies, heat stations, capacitors, high-frequency output stages, induction coils, water systems, quench systems, and fixturing.

This chapter discusses quality control programs and procedures for induction heat-treating systems and includes related forms and checklists.

To ensure consistency, quality of results, and documentation compliance, audits are required when heat treating. This chapter introduces basic parts of the ISO certification program.

This chapter provides a discussion of nitriding furnace equipment and control systems. The discussion covers the essential design criteria of the furnace, types of nitriding furnaces, insulation for the reduction of furnace heat losses, and factors influencing furnace configuration and design. It also covers the processes involved in the construction and maintenance of retorts, methods for sealing a retort to prevent ammonia leaks, and safety precautions to be taken while using ammonia. Further, the chapter provides information on the factors for choosing a heating medium and discusses the processes involved in controlling temperature, gas dissociation, oxygen probes, and nitriding sensors.

Many companies conduct only metallurgical evaluations in the wake of failures, discovering nothing more than the physical mechanism by which the failure occurred. The origin of failures, however, is often complex, involving not only physical mechanisms, but also human behavior and latent factors. Failures may also involve multiple parts, entire machines, or processes of any size and shape. The chapter examines the unique aspects of many failures and explains how they can sometimes be traced to systemic issues. It also covers the reasons why products fail, including improper service or operation, improper maintenance, improper testing, assembly errors, fabrication or manufacturing errors, and design errors. The case of the Tacoma Narrows Bridge collapse is presented to illustrate the consequence of overlooked factors, in this case, wind dynamics, and the importance of identifying root causes to prevent repeat failures.

Corrosion can be defined as a chemical or electrochemical reaction between a material, usually a metal, and its environment that produces a deterioration of the material and its properties. This chapter describes the effects and economic impact of corrosion in major industrial plants. The emphasis in this chapter, as well as in other chapters in this book, is on aqueous corrosion, or corrosion in environments where water is present. The chapter describes the classification of various forms of corrosion based on the nature of the corrodent, mechanism of corrosion, and appearance of the corroded metal. It discusses five primary methods of corrosion control, namely, material selection, coatings, inhibitors, cathodic protection, and design. Examples of the opportunities in corrosion control and the means to implement a program to capitalize on those opportunities are presented in a table. The chapter concludes with varied sources of information pertaining to corrosion and corrosion prevention.

This chapter provides guidelines on how to set up and run an effective quality-improvement program for aluminum extrusion operations. It begins by identifying production processes and variables that impact the quality of hard and soft alloy extrusions. It then presents a series of checklists and flowcharts that can be used to monitor and troubleshoot billet-making and extrusion processes, die construction, equipment maintenance, heat treating, and sawing and stretching procedures. It also discusses the importance of charting test results and monitoring surface treatments that may be required to improve corrosion, oxidation, or wear resistance.

This chapter covers the different types of extrusion presses in use, discussing their relative advantages, operating parameters, and selection factors. It describes the function of major components, including containers, stems, dummy pads, and die carriers, the maintenance they require, and their impact on productivity and the quality of extrusions. It also discusses the integration of auxiliary equipment such as log heaters and shears, quench systems, die ovens, pullers, stretchers, and stackers.

The design process is the first and most important step in corrosion control. Major savings in operating costs are possible by anticipating corrosion problems so as to provide proper design for equipment before assembly or construction begins. This chapter describes the role of the design team in producing a successful final design, general considerations in corrosion-control design, and design details that accelerate corrosion. The details that must be considered when attempting to control corrosion by design include plant/site location, plant environment, component/assembly shape, fluid movement, surface preparation and coating procedures, and compatibility, insulation, and stress considerations. Design solutions for specific forms of corrosion, namely crevice corrosion, galvanic corrosion, erosion-corrosion, and stress-corrosion cracking, are then considered. A brief section is devoted to the discussion on corrosion allowance used for steel parts subject to uniform corrosion. Finally, the chapter describes the design considerations for using weathering steels.

This chapter identifies the primary causes of service failures and discusses the types of defects from which they stem. It presents more than a dozen examples of failures attributed to such causes as design defects, material defects, and manufacturing or processing defects as well as assembly errors, abnormal operating conditions, and inadequate maintenance. It also describes the precise usage of terms such as defect, flaw, imperfection, and discontinuity.

This chapter focuses on various factors to be considered at design stage to minimize corrosion. It begins by providing information on design considerations and general corrosion awareness. This is followed by a description of several factors influencing materials-component failure. Details on design and materials selection, which assist in controlling corrosion, are then provided. The chapter ends with a discussion on the design factors that influence corrosion.

This appendix is a comprehensive collection of selected sources related to corrosion properties of materials and corrosion testing.

This chapter provides an overview of environmental factors when studying a gear failure. Environmental factors discussed are lubrication, temperature, and mechanical stability.

In this chapter, the fundamental concepts of different types of extrusion presses and major press components are discussed. An outline of the recently integrated system, from billet furnaces and log shears to age ovens and stacking equipment to control the entire manufacturing process with high productivity, is also included. The major press and tooling components of basic types of extrusion presses for making solid sections, bars, strips, rods, tubes, and hollow sections are shown. Auxiliary and handling equipment is discussed.

This chapter provides an outline of the failure modes and mechanisms associated with most boiler tube failures in coal-fired power plants. Primary categories include stress rupture failures, water-side corrosion, fire-side corrosion, fire-side erosion, fatigue, operation failures, and insufficient quality control.

This chapter presents the salts used and the process advantages of salt bath nitriding. It describes bath testing and analysis including the materials and equipment, analysis procedure, and determination of sodium carbonate and sodium cyanate for titration testing of the nitriding salt bath. The chapter explains the procedures for maintenance of the salt bath and related equipment. It also discusses safety precautions and design parameters for furnace equipment.

This chapter discusses corrosion prevention methods used with aluminum and its alloys. The methods range from relatively straightforward measures, such as proper handling and storage, to advanced early warning corrosion monitoring systems for military aircraft. The chapter summarizes the basic factors that influence design for corrosion resistance and discusses the use of conversion coatings, organic coatings, porcelain enameling, and electroplating. It also discusses corrosion monitoring methods used in chemical processing and refining industries.

This chapter deals with the technology of stainless steel as it pertains to its proper use in architecture, art, and construction. It begins with an overview of the corrosion resistance of stainless steel, providing guidelines for balancing corrosion resistance, processing characteristics, and economy. This is followed by sections describing the influence of surface finish on corrosion resistance of stainless steel and reviewing some of the factors pertinent to balancing service environment, design requirements, and maintenance considerations. The chapter then discusses the various factors pertinent to important considerations in buildings, namely surface finish aesthetics, flatness, maintenance, repair, fabrication, and service considerations. It ends with a section providing information on concrete reinforcing bar.

This chapter is a detailed account of the applications of stainless steel in automotive and transport systems. The discussion covers exhaust systems, structural components, automotive components, trucks, and rail transport.

This chapter provides a brief review of industry’s battle with fatigue and fracture and what has been learned about the underlying failure mechanisms and their effect on product lifetime and service. It recounts some of the tragic events that led to the discovery of fatigue and brittle fracture and explains how they reshaped design philosophies, procedures, and tools. It also discusses the influence of material and manufacturing defects, operating conditions, stress concentration and intensity, temperature and pressure, and cyclic loading, all of which play a role in the onset of fatigue cracking and thus should be considered when predicting useful product life.