Abstract
Uniformity of toughness of carbon steel wire, such as in spinning-pins and springs etc. is an essential matter. The temperability is affected by various conditions of previous treatment. So, the authors have studied the effect of quenching conditions upon the temperability and the initial structure of carbon-steel wire, by tests of the toughness and observations of the microstructure of specimens of C: 0.62, Mn: 0.43, Si: 0.28, dia: 1.625 mm. The results obtained were as follows:—(1) The difference of the temperability is due to the difficulty of uniform dissolution of cementite in austenite. (2) In the case the initial structure is spheroidal, the degree of the temperability is smaller than in the case it is lamellar. (3) In order to equalize the toughness of spinning-pins and springs etc. which are produced by rapid heating on mass-production system, it is neccessary to control equally the temperature and the time of quenching, and futhermore to homogenize the initial structure.
