| 摘要 |
PURPOSE:To heat treat surely only an untreated ring in a heat treating furnace by enveloping heat treated rings placed in a furnace together with the untreated ring in enveloping members so that proper spaces are left and by heating the untreated ring while circulating a fluid for cooling through the spaces. CONSTITUTION:Part of a long-sized chain 2 having heat treated rings 6, 7 and an untreated ring 5 connecting the rings 6, 7 is set in the heat treating furnace 1. At this time, at least parts of the rings 6, 7 drawn into the furnace 1 are enveloped in enveloping members 11 such as iron plates in a tightly sealed state so that spaces 12 of proper size are left. A fluid for cooling such as air is circulated through the spaces 12, and the connecting ring 5 is heated to a hardening temp. The chain 2 is then taken out of the furnace 1, and the heated ring 5 is quenched to carry out hardening. |
