研削, ラッピングおよびバレル仕上が13Cr鋼の疲労強度に及ぼす影響

抄録

This paper reports the result of experiments made of the effect of grinding, lapping and barrel-finishing operations on the fatigue strength of quenched and tempered 13Cr stainless steel used for compressor valve. The reversed plane-bending fatigue tests were carried out by means of Schenk-type fatigue testing machine of 10kgm at about 1500rpm. The results obtained can be summarized as follows:
(1) In longitudinal grinding the fatigue limit of roughly ground specimens was almost the same as finely ground ones, but in transverse grinding the latter was about 10% higher than the former.
(2) In rough grinding the fatigue limit of transversely ground specimens was contrary to general expectations, nearly equal to that of longitudinally ground ones, but in fine grinding the former was about 20% higher than the latter.
(3) The lapped specimens, when barrel-finished, get their surface roughness reduced by half, with but little increase in fatigue limit.
(4) In the surface finishing operations under the conditions used in this experiment it was necessary that the residual stress both in the surface layer and the surface roughness should be taken into consideration as having influence on the fatigue strength.