Abstract: A high strength and corrosion resistant titanium alloy having excellent corrosion-wear properties may be prepared in that Al and Mo are added as alloying elements in specific amounts, and if Zr in a specific amount is further added, the strength and the corrosion-wear properties would be more improved.

Abstract: A .beta. type titanium alloy material is passed through processes and heating treatments of cold working--intermediate solution treatment--final cold working--final solution treatment--aging. In this process, a structure, which has been provided with strains by the cold working performed prior to the final cold working, will be changed into a recrystallized structure by carrying out the intermediate solution treatment, where uniform and fine micro substructure of dislocations, remain with grains. If such an intermediate solution-treated material is processed with a slight cold working by the final cold working and further with the solution treatment, only a recovery phenomenon progresses, and it is possible to provide such a micro substructure containing more uniform and finer dislocation network not only in grains but also in grain boundaries. Therefore, in the aging, expedition of precipitation and uniform distribution of .alpha.

Abstract: Low nonmagnetic steel having a thermal expansion coefficient of 1.0.about.1.3.times.10.sup.-5 /.degree. C. and a high yielding point of higher than 36 Kg/mm.sup.2 consists of less than 0.5% by weight of C, less than 2% by weight of Si, 20.about.30% by weight of Mn, and 0.005.about.0.04% by weight of N and the balance of iron and impurities, wherein the following relationships between the amounts of C and Mn are simultaneously satisfied.Mn (%)>16.times.C (%)+18Mn (%)>-12.times.C (%)+21.5The steel described above is heated to a temperature of less than 1220.degree. C., and then hot rolled. A finishing rolling temperature is maintained to be less than 800.degree. C.+400.degree. C..times.C (%) depending upon the amount of carbon. After cold working the nonmagnetic steel has a permeability of less than 1.1.

Abstract: Low nonmagnetic steel having a thermal expansion coefficient of 1.0.about.1.3.times.10.sup.-5 /.degree.C. and a high yielding point of higher than 36 Kg/mm.sup.2 consists of less than 0.5% by weight of C, less than 2% by weight of Si, 20.about.30% by weight of Mn, and 0.005.about.0.04% by weight of N and the balance of iron and impurities, wherein the following relationships between the amounts of C and Mn are simultaneously satisfied.Mn(%)>16.times.C(%)+18Mn(%)>-12.times.C(%)+21.5The steel described above is heated to a temperature of less than 1220.degree. C., and then hot rolled. A finishing rolling temperature is maintained to be less than 800.degree. C.+400.degree. C..times.C(%) depending upon the amount of carbon. After cold working the nonmagnetic steel has a permeability of less than 1.1.