Effect of electron-beam melting upon the properties of grade ShKh15 ball-bearing steel

A study of early corrosion behaviors of FeCrAl alloys in liquid lead–bismuth eutectic environments

“…It is difficult to discuss the long-term stability of Al 2 O 3 on the FeCrAlY coating layer with respect to S segregation effect because there is no information on the amount of S in the coating layer. However, it could be expected that the amount of S in FeCrAlY layer can be reduced during re-melting process by intense pulsed electron beams (GESA) [16]. Furthermore, the re-melting process by GESA can lead to a very fine grain microstructure on coating layer [17] which is generally effective to enhance the self-healing capability of oxide layer.…”

Hydrogen embrittlement in bearing steels

“…Degassing at a low temperature (<200 o C) can liberate weakly trapped hydrogen and concentrate it in deeply trapping microstructural features which can, in some cases, increase the embrittlement susceptibility due to higher stress concentrations [31]. With current commercial as-rolled 52100 steels, the total hydrogen content permissible is said to be around 1 ppm, although electron beam melted 52100 type steel has been shown to contain as little as 0.4 ppmw [14] [59]. The mean total hydrogen content for a 52100 15 mm diameter bar can be as high as 8 ppm, the distribution is fairly uniform but ranges from 7-15 ppm to 0.5-2.5 ppm at the surface and core respectively, these contents are reduced during further processing [14] [60].…”

“…31 With current commercial as-rolled 52100 steels, the total hydrogen content permissible is said to be around 1 ppm, although electron beam melted 52100 type steel has been shown to contain as little as 0.4 ppmw. 14,58 The mean total hydrogen content for a 52100 15 mm diameter bar can be as high as 8 ppm, the distribution is fairly uniform but ranges from 7-15 ppm to 0.5-2.5 ppm at the surface and core, these contents are reduced during further processing. 14,59 Hydrogen trapping with in-life degassing, through-life hydrogen trapping and hydrogen ingress prevention are possible means to reduce hydrogen embrittlement.…”

“…With current commercial as-rolled 52100 steels, the total hydrogen content is typically around the order of magnitude of 1 ppm, although electron beam melted 52100 type steel has been shown to contain as little as 0.4 ppmw. 14, 58 The mean total hydrogen content for a 52100 15 mm diameter bar during the manufacturing of the steel can be as high as 8 ppm; this content is reduced during further processing. 14, 59 The hydrogen concentrations achievable in a variety of M50 bearing steel production processes are shown in Table 3.…”