Search Results for temperature

This data set contains the results of uniaxial tensile tests of a wide range of aluminum casting alloys conducted at high temperatures from 100 to 370 deg C, subzero temperatures from -269 to -28 deg C, and room temperature after holding at high temperatures from 100 to 370 deg C. In most cases, tests were made of several lots of material of each alloy and temper. The results for the several lots were then analyzed together graphically and statistically, and the averages were normalized to the room-temperature typical values. For some alloys, "representative" values (raw data) rather than typical values are provided.

This appendix contains a temperature conversion table listing the temperature readings (in deg F) to be converted and equivalent Celsius temperature values.

Temperature is a critical process parameter in the heat treatment and forging of steel and must be accurately measured to properly control it. This appendix discusses the operating principles of thermocouples and infrared pyrometers, describing the various types as well as advantages and applications.

This chapter discusses the factors that influence temperature in forging operations and presents equations that can be used to predict and control it. The discussion covers heat generation and transfer, the effect of metal flow, temperature measurement, testing methods, and the influence of equipment-related parameters such as press speed, contact time, and tooling geometries.

This appendix contains a temperature conversion table listing temperatures to be converted, along with degree Centigrade or Fahrenheit equivalent.

This chapter discusses three measurements parameters: temperature, strain, and magnetic field strength. It stresses the measurement of temperature because it is the primary variable in nearly all low-temperature material properties. The chapter contains information on methods and auxiliary materials. Areas of frequent concern, such as thermal contact, heat leak, thermal anchoring, thermal conductivity of greases, insulators, lead wires, ground loops, and feedthroughs are also reviewed. The chapter provides an overview and historical development of temperature scales because the practical use of all thermometers is associated with some approximation of the thermodynamic temperature scale. A short section is devoted to types of temperature measuring devices. The characteristics of commercially available resistance-type strain gauges at low temperatures are stressed.

This chapter focuses on resistance characteristics and methods of protecting different forms of high-temperature gaseous corrosion, namely high-temperature oxidation, sulfidation, carburization, hydrogen effects, and hot corrosion.

This chapter compares and contrasts the high-temperature behaviors of metals and composites. It describes the use of creep curves and stress-rupture testing along with the underlying mechanisms in creep deformation and elevated-temperature fracture. It also discusses creep-life prediction and related design methods and some of the factors involved in high-temperature fatigue, including creep-fatigue interaction and thermomechanical damage.

This chapter describes the corrosion behavior of beryllium in gaseous atmospheres, including oxygen, nitrogen, carbon dioxide, and carbon monoxide. It also discusses the development of high-temperature corrosion-resistant beryllium alloys.

This chapter describes the two types of Time-Temperature-Transformation (TTT) diagrams used and outlines the methods of determining them. As a precursor to the examination of the decomposition of austenite, it first reviews the phases and microconstituents found in steels. This includes a presentation of the iron-carbon phase diagram and the equilibrium phases. The chapter also covers the common microconstituents that form in steels, including the nomenclature used to describe them. The chapter provides a comparison of isothermal and continuous cooling TTT diagrams. These diagrams are affected by the carbon and alloy content and by the prior austenite grain size, and the way in which these factors affect them is examined.

This chapter explains how materials selection becomes much more difficult when designing for high-temperature corrosion environments. It also discusses the use of cladding and weld overlays to compensate for material deficiencies and prolong service life.

The mechanical properties of steel are strongly influenced by the underlying microstructure, which is readily observed using optical microscopy. This chapter describes common room-temperature steel microstructures and how they are achieved via heat treatment. It discusses the production of hypo- and hypereutectoid steels and the effect of cooling rate on microstructure. It also examines quenched steels and the phase transformations associated with rapid cooling. It describes the development of lath and plate martensite, retained austenite, and bainite and how to identify the various phases. The chapter concludes with a brief review of spheroidized microstructures.

Elevated-temperature failures are the most complex type of failure because all of the modes of failures can occur at elevated temperatures (with the obvious exception of low-temperature brittle fracture). Elevated-temperature problems are real concerns in industrial applications. The principal types of elevated-temperature failure mechanisms discussed in this chapter are creep, stress rupture, overheating failure, elevated-temperature fatigue, thermal fatigue, metallurgical instabilities, and environmentally induced failure. The causes, features, and effects of these failures are discussed. The cooling techniques for preventing elevated-temperature failures are also covered.

Fiber-reinforced metal-matrix composites have carved out a niche in applications requiring high strength to weight ratios, but they are susceptible to failure when exposed to high temperatures and cyclic loads. This chapter discusses the obstacles that must be overcome to improve the creep-fatigue behavior of these otherwise promising materials. It addresses six areas that have been the focus of intense research, including thermal-expansion and elastic-viscoplastic mismatch, thermally induced biaxiality and interply stresses, creep and cyclic relaxation of residual stresses, and enhanced interfaces for oxidation.

This chapter defines low-temperature and cryogenic steels and describes their alloy classifications and their ambient and low-temperature properties. These steels include ferritic carbon and low alloy steels, martensitic low alloy steels, martensitic high alloy steels, and austenitic high alloy steels.

This chapter details low-temperature test procedures and equipment. It discusses the role temperature plays in the properties of typical engineering materials. The effect that lowering the temperature of a solid has on the mechanical properties of a material is summarized for three principal groups of engineering materials: metals, ceramics, and polymers (including fiber-reinforced polymers). The chapter describes the factors that influence the selection of tensile testing procedures for low-temperature evaluation, along with a comparison of tensile and compression tests. It covers the parameters and standards related to low-temperature tensile testing. The chapter discusses the factors involved in controlling test temperature. Finally, the chapter discusses the safety issues concerning the use of cooled methanol, liquid-nitrogen, and liquid helium.

This appendix consists of tables listing temperatures recommended for austenitizing carbon and low-alloy steels prior to hardening.