On the High Frequency Pressure-Welding of Rail

Abstract

Recent trend in railroads in definitely toward use of long rails. In Japan also, this trend is increasingly obvious.
The production of weld rails has been started for this purpose. We began to develop the technic of pressure welding by High frequency., making it possible for us to regularly produce weld rails.
Follwing is characteristics of this welding process and the sammaries of results of various tests on weld rails.
(1) The most important characteristics of the high frequency pressure welding method are that the reliability on the reproducibity of the joint strength is large, and that the strength is very large.
(2) Necessary conditions required for successful performance of high frequency pressure weld-ing are that the upset is made after satisfactory heating.
Satisfactory joints are obtained under similar welding conditions for both 50T and 50N Rails.
(3) According to the results of bending tests performed with pressure welded actual rails, the strength was 112, 500-122, 000 Kg for head up and 113, 500-127, 000 Kg for head down with 50T pressure welded rails.
These values are larger than the values specified by the National Railways for pressure welded rails by more than 10, 000 Kg. These values are quite satisfactory.
(4) By the falling weight test performed by the step up method based upon the JIS specific-ations, the non breakage height of 50 N Rails was 2 m at the least and 3.5 m at the most, and those of 50 T Rails were 3 m at the least and 5 m at the most.
These are much above the specifications given by the Notional Railways. These results are better than those of Rails, welded by different methods, namely, flush butt welded Rails, . Gas pressure welded Rails, and so on.