METHOD FOR MANUFACTURING OF GRATES OF BURNING TROLLEYS WITH INCREASED OPERATING LIFE Russian patent published in 2019 - IPC C21D9/00 C22C38/40 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, namely to production of grates of burning trolleys from cast heat-resistant steel. Steel is poured, containing, in wt. %: carbon 0.30–0.40, silicon 0.50–2.00, manganese 0.30–0.80, sulphur not more than 0.030, phosphorus not more 0.035, nickel 11.00–13.00, chromium 22.00–26.00, iron and admixtures - balance, to produce grates. Performing their thermal treatment by quenching in air at temperature of 1100 °C for 80 minutes and tempering at temperature 900 °C for 150 minutes with subsequent cooling in furnace or on air. As impurities, steel contains up to 0.07 wt. % of aluminium and cobalt in amount of up to 0.50 wt. %.

EFFECT: raised (minimum) service life of grate bars from steel at operation in conditions of aggressive atmospheres with content of nitrogen and sulphur oxides at constant heat changes at temperature range of 20–1100 °C and with possibility of maintenance of short-term heating up to 1320 °C.

3 cl, 7 dwg, 6 tbl