Search Results for fluidized-bed quenching

The fluidized bed provides a means for exchanging heat between a metal part, the solid particles, and the fluidizing gas and which is viable for quenching. This article briefly considers the design aspects of the gas distributor, plenum, container, immersed cooling tubes and surface air spray cooling system in the quenching fluidized bed. It describes the fundamental factors affecting quenching power of the fluidized beds, namely, particle size, particle material, fluidizing gas composition, fluidizing gas flow rate, bed temperature and pressure, and the arrangement of quenched parts with respect to one another and to the bed. The article discusses the advantages, disadvantages, various applications and processes, including conventional batch quenching, two-step batch quenching, and continuous quenching of fluidized bed quenching, in detail.

This article presents a detailed discussion on the characteristics, types, properties, quenchants, applications, advantages, and disadvantages of various types of quenching: air quenching, water quenching, rinse quenching, time quenching, press quenching, delayed quenching, fluidized-bed quenching, ultrasonic quenching, intercritical quenching, subcritical quenching, ausbay quenching, hot isotactic press quenching, slack quenching, differential quenching, and double quenching.

This article discusses the important characteristics of fluidized beds. The total space occupied by a fluidized bed can be divided into three zones: grid zone, main zone, and above-bed zone. The article discusses the various types of atmospheres of fluidized beds, such as oxidizing and decarburizing atmosphere; nitrocarburizing and nitriding atmosphere; carburizing and carbonitriding atmosphere; and chemical vapor deposition atmosphere. External resistance heating, external combustion heating, internal resistance heating, direct resistance heating, submerged combustion heating, and internal combustion heating can be used to achieve the heat input for a fluidized bed. The article also describes the operations, design considerations, and applications of fluidized-bed furnaces in heat treating. Thermochemical surface treatments, such as carburizing, carbonitriding, nitriding, and nitrocarburizing, are also discussed. Finally, the article reviews the principles and applications of fluidized-bed heat treatment.

This article provides a detailed discussion on the heating equipment used for austenitizing, quenching, and tempering tool steels. These include salt bath furnaces, controlled atmosphere furnaces, fluidized-bed furnaces, and vacuum furnaces. The article discusses the types of nitriding and nitrocarburizing processes and the equipment required for heat treating tool steels to improve hardness, wear resistance, and thermal fatigue. The various nitriding and nitrocarburizing processes covered are salt bath nitrocarburizing, gas nitriding and nitrocarburizing, and plasma nitriding and nitrocarburizing.

Batch furnaces and continuous furnaces are commonly used in heat treating. This article provides a detailed account of various heat treating equipment and its furnace types, including salt bath equipment (externally heated, immersed-electrode and submerged-electrode furnaces), and fluidized-bed equipment (external-resistance-heated fluidized beds). It describes various auxiliary equipment used in cold-wall furnaces, namely, heating elements and pumping systems. Five types of heat-resistant alloys are used for furnace parts, trays, and fixtures: Fe-Cr alloys, Fe-Cr-Ni alloys, Fe-Ni-Cr alloys, nickel-base alloys and cobalt-base alloys. The article lists the recommended applications for alloys for parts and fixtures for various types of heat treating furnaces.

This article provides an overview of heat treatment processes, namely, solution heat treatment, quenching, natural aging, and artificial aging. It contains a table that lists the various heat treatment tempers commonly practiced for nonferrous castings. The article describes microstructural changes that occur due to the heat treatment of cast alloys.