Elektrofunkenerosive Bearbeitbarkeit von vergütbaren Warmarbeitsstählen und ledeburitischen Chromstählen

Hribernik, Bruno; Russ, Franz

doi:10.1002/srin.198205410

Cited by 2 publications

(2 citation statements)

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“…However, next to the lath martensite, only an annealed structure was found, in which region the temperature increased to below 1000°C and the structure was not austenized; thus, an annealed ferrite structure with a lower dislocation density was developed. Many researchers [7,16,17] have proved that a white layer of martensitic structure was developed on the surface processed by EDM. However, both fine martensite and annealed structures were observed on the cutting surface in this study.…”

Section: Microstructure Of the Rough-cut Surface Processed By Wedmmentioning

confidence: 99%

“…Therefore, craters are formed on both electrodes with each spark-namely, a large one formed on the workpiece and a smaller one on the wire electrode. Besides the surface defects such as cracks, gas voids, plastic deformation, and the buildup of residual stress caused by the rapid cooling rate at the end of discharging, [4][5][6][7] a recast layer is always formed on the electrical-discharged surface, which is composed of several microscopic metallurgical layers, dependent on the machining conditions, electrode materials, and discharge mechanisms. [4,6,8,9] Although WEDM has been used for many decades, few works have studied the microstructure of the recast and *PHILIPS is a trademark of Philips Electronic Instruments Corp., Mahwah, NJ.…”

Section: Introductionmentioning

confidence: 99%

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Characteristics of the rough-cut surface of quenched and tempered martensitic stainless steel using wire electrical discharge machining

Huang

Yao³

et al. 2004

Metall Mater Trans A

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This article studies the surface characteristics of quench-and temper-treated AISI 440A martensitic stainless steels, which were rough cut using wire electrical discharge machining (WEDM). The microstructure of the recast layer on the cut surface was investigated using scanning and transmission electron microscopes, and the phase compositions were analyzed with an energy-dispersive X-ray (EDX) spectrometer. Experimental results showed that the thickness of the recast layer varied with the heat-treatment condition of the workpiece, the largest thickness was obtained with a quenched specimen, and the thickness decreased with increasing tempering temperature. Intergranular surface cracks were observed only from the as-quenched specimen, whereas surface cracks were not found in the rough-cut specimens after tempering above 200°C. It is reckoned that reliefing of the thermal residual stress in the quenched workpiece induced the surface intergranular cracks. Microstructures of the recast layer on the rough-cut surfaces of the 600°C tempered specimen were examined using cross-sectional transmission electron microscopy (TEM) specimens. An amorphous layer exists at some parts of the outermost cut surface. A high density of wire electrode droplets of spherical shape, approximately 10 to 60 nm in size, was found throughout the porous recast layer. Besides, many highchromium containing sigma spheres with sizes of approximately 120 to 200 nm were precipitated at the bottom part of the recast layer, and its formation mechanism was proposed. Adjacent to the recast layer was a heat-affected zone (HAZ) with a thickness of about 4 m, in which temper-induced carbides were fully dissolved. The HAZ comprised basically two distinct regions: the first region adjacent to the recast layer was composed of a lath martensite structure, while the other region was an annealed ferrite structure.

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Section: Microstructure Of the Rough-cut Surface Processed By Wedmmentioning

confidence: 99%