The invention provides a steel grade of a bergol cannula with
high intensity and high
toughness, wherein the propositions of composition elements are that C 0.22-0.4%, Si 0.17-0.35%, Mn 0.45-0.60%, Cr 0.95-1.10%, Mo 0.70-0.80%, Al 0.015-0.040%, Ni<0.20%, Cu<0.20%, V 0.070-0.100%, Ca>0.0015%, P<0.010%, S<0.003% and the allowance is iron. The invention also provides a method for rolling the bergol cannula, which comprises the following steps: firstly,
smelting batching, secondly, continuously
casting and rolling, thirdly,
processing a
pipe. The method has the advantages of embodying steel grade with higher
alloy content is adopted through the method, excellent
mechanical property and lower production cost, the making of perforation and rolling techniques are reasonable,
mechanical property of cannual is maximally improved, the selection of heat treatment process technique and thermal straightening temperature are reasonable, grain
fineness numbers of tissues are refined, residual
tension stress of the cannula is greatly lowered, geometric precision control range is strictly planned, and the property of the cannula is improved under the circumstance of reasonable production cost.