抄録
Special features of recent cast iron rolls was briefly outlined as follows:
1) Though grain rolls were used widely in every steel works, such defects as skin roughness and neck-breaking could not be improved for the present in the invetigation of the Roll Research Committee of the Iron and steel Instiute of Japan
2) Plain chilled rolls had become to be manufactured perfectly almost without defects. Alloy chilled rolls of nickel-chromium series or manganse-silicon series had extremely high hardness and superior quality, and in the recent years the effect of additional element as vanadium, titanium, boron, tellurium and zirconium etc, on alloy chilled rolls have been studied in every field.
3) Dead locks in manufacturing technigue of alloy chilled rolls wruld be broken by the development of manufacture of compound rolls.
4) Displaced compound rolls (duplex rolls) became to be put in to practical use in every country recently, and especially they were used as working rolls. The core material of displaced compouud rolls had been changed from cast iron to cast steel.
5) Sleeve chilled rolls were put in to practical use in steel works of America and Germany, but in Japan it was in the stage of trial manufacture.
6) Centrifugal casting chilled rolls were going to be manufatured for trial in America, but its design had not been found in Germany.
7) Cast carbide chilled rolls, of which the shell was a carbide-rich material with high hardness and the core was a tough material, were used as hot-working rolls in Japan.
8) It was very difficult for grooved chilled rolls to be manufactured without defects, and so in Germany grooved grain rolls were substituted for it. In Japau two and three grooved chilled rolls were manufactured with good results and the rolled capacity by it was twice or three times as much as by grooved grain rolls and sand grooved rolls.
9) Though it wes necessary especially to carry out the heat-treatment of alloy chilled rolls in order to eliminate the internal stress of it, it was not put in to practical use yet, but it was carried out in general to heat-treat the neck of rolls for the sake of prevention of neck-breaking.
