The invention discloses a high-strength and low-expansion hot-rolled
invar alloy. The high-strength and low-expansion hot-rolled
invar alloy comprises, by weight, 0.1%-0.4% of C, 34%-42% of Ni, 1.5%-5.5% of Mo, 0.002%-0.03% of N, 0.015%-0.04% of Al, 0.005% or less of S, 0.005% or less of P, one or more of 0.01%-0.4% of Nb, 0.005%-0.55% of V and 0.02%-0.2% of Ti, and the balance Fe and inevitable impurities. According to the
alloy, the content of S and the content of P are controlled strictly; the content of
nitrogen in the alloy is effectively increased, and elements such as Nb, V, Ti and Mo are added properly, in this way, under the premise that the low
thermal expansion coefficient of the alloy is guaranteed, the tensile strength of an
austenite hot-rolled matrix is enhanced by means of composite dispersed
precipitation of nitrides and carbides, and a high-quality base material is provided for further development of products such as cold-drawn
invar alloy wires. According to the alloy, fine particles of NbN,
TiN, VN, VC, Mo2C, NbC and the like are dispersively distributed on the
austenite matrix, so that the tensile strength is effectively improved, and the expansion coefficient is reduced. The high-strength and low-expansion hot-rolled
invar alloy has the characteristics that production cost is low, the operation process is simple, and the raw materials of the alloy are saved.