| 摘要 |
Steel for railway and tram point crossing frog castings, according to this invention, includes iron of mass % from 0,15% to 0,20 % of carbon, 1,00 % to 1,80% of mangan, 1,00% to 1,60 of silicon 1,50% to 2,50 % of chromium, 2,50% to 3,50% of nickel, 0,40 % to 0,70 % of molybdenum and 0,0025 % to 0,0005% of boron. Therewith carried out is thermal treatment for baintic structure and wherefrom obtained steel has the least strength of extension is 1100 MPa, and the least extension limit is 1400 MPa, while the top loading amounts to 20 J and the least hardness of breakage amounts to 100 MPa/m ½.Steel according to this technical solution may be suitably used mainly for castings of railway and tram point crossing frog castings for huge axial loadings and spots with great frequency of vehicles. |
