外文翻譯--材料選擇與熱處理-在線瀏覽
2025-01-06 02:07本頁面
【正文】 en the result of improper material use, has had a marked impact. In addition, the interdependence between materials and their processing has bee better recognized. The development of new processes often forces reevaluation of the materials being processed. Therefore, it is imperative that design and manufacturing engineers exercise considerable care in selecting, specifying, and utilizing materials if they are to achieve satisfactory results at reasonable cost and still assure quality. The first step in the manufacture of my product is design, which usually takes place in several distinct stages: (a) conceptual。 (b) functional。 (b) failure to foresee, and take into account the reasonable uses for the product (where possible, the designer is farther advised to foresee and account for misuse of the product, as them have been many product liability cases in recent years where the claimant, injured during misuse of the product, has sued the manufacturer and won)。 (d) inadequate, and unverified, quality control procedures。 for most ferrous alloys, normalizing and annealing are not synonymous. Normalizing usually is used as a conditioning treatment, notably for refining the grains of steels that have been subjected to high temperatures for fing or other hot working operations. The normalizing process usually is succeeded by another heat treating operation such as austenitic for hardening, annealing, or tempering. Annealing is a generic term denoting a heat treatment that consists of heating to and holding at a suitable temperature followed by cooling at a suitable rate. It is used primarily to soften metallic materials, but also to simultaneously produce desired changes in other properties or in microstructure. The purpose of such changes may be. 5 but is not confined to, improvement of mach inability, facilitation of cold work (known as inprocess annealing), improvement of mechanical or electrical properties, or to increase dimensional stability. When applied solely to relieve stresses, it monly is called stressrelief annealing, synonymous with stress relieving. When the term” annealing is applied to ferrous alloys without qualification, full annealing is implied. This is achieved by heating above the alloy’s transformation temperature, then applying a cooling cycle which provides maximum softness. This cycle may vary widely, depending on position and characteristics of the specific alloy. Quenching is the rapid cooling of a steel or alloy from the austenitic temperature by immersing the work piece in a liquid or gaseous medium. Quenching media monly used in chide water, 5%brine, 5%caustic in an aqueous solitaire or gas (usually air or nitrogen). Selection of a quenching medium depends largely on the harden ability of the material and the mass of the material being treated(principally section thickness). The cooling capabilities of the abovelisted quenching media vary greatly. In selecting a quenching medium, it is best to avoid a solution that has more cooling power than is needed to achieve the results, thus minimizing the possibility of cracking and warp age of the parts being treated, Modifications of the term quenching include direct quenching, fog quenching, hot quenching, interrupted quenching selective quenching, spray quenching, anti time quenching. Tempering. In heat treating of fe
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