The invention discloses a method about the integration of the metallurgical purification of metallic gadolinium and the preparation of gadolinium oxide nanoparticles (GONPs) by arc plasma. The method includes the metallurgical purification and the nanoparticle preparation. Firstly, the gadolinium ingot and a tungsten rod respectively act as an anode and a cathode. After the arc furnace is evacuated and then is filled with a working atmosphere, impurities in the gadolinium ingot are removed in the form of volatilization to obtain purified gadolinium by the first arc discharge. Whereafter, the purified gadolinium and the tungsten rod are used as the anode and cathode. After the arc furnace also is evacuated and then also is filled with a working atmosphere, GONPs are obtained from the inner wall of the arc furnace though the second arc discharge. The metallurgical purification of metallic gadolinium and the preparation of GONPs were integrated by arc plasma.

Magnetic field components are measured at multiple longitudinal positions and used to calculate estimated longitudinal position and length of a transversely localized electric current segment flowing across a gap between conductive bodies. The apparatus can be used with a remelting furnace. The electrode and ingot act as the conductive bodies, and arcs, discharges, or slag currents are the current segments spanning the gap. Actuators for movable sensors can be coupled to the sensors in a servomechanism arrangement to move the sensors along with the moving gap. An actuator for moving one of the conductive bodies can be coupled to sensors in a servomechanism arrangement to maintain the gap distance within a selected range as the gap moves.

A multicomponent FeCoSiM soft magnetic alloy is provided. M of the alloy is one or more of V, Cr and Ni. A sum of atomic percentages of alloy elements in the alloy is 100%. The atomic percents of the alloy elements meet the following conditions: Fe, 68˜78 at %; Co, 4˜12 at %; Si, 14˜18 at %; V, 0˜4 at %; Cr, 0˜4 at %; and Ni, 0˜4 at %. The preparation method of the alloy includes weighing raw materials according to the atomic percentages of the alloy elements and then performing melting and annealing heat treatment each in vacuum or a protective atmosphere. The alloy is obtained by a reasonable design of compositions and contents. A magnetocrystalline anisotropy constant of the alloy is low, a magnetostrictive coefficient of the alloy approaches zero and the alloy has characteristics of high saturation flux density and low coercivity.

Disclosed herein is a method for deoxidizing an Al—Nb—Ti alloy, which includes melting and holding an Al—Nb—Ti alloy containing from 50 to 75 mass % of Al, from 5 to 30 mass % of Nb, and 80 mass % or less in total of Al and Nb by a melting method using a water-cooled copper vessel in an atmosphere of 1.33 Pa to 2.67×10.sup.5 Pa at a temperature of 1,900 K or more, thereby decreasing an oxygen content thereof. The Al—Nb—Ti alloy is prepared using an alloy material formed of an aluminum material, a niobium material and a titanium material and containing oxygen in a total amount of 0.5 mass % or more.

Disclosed herein is a method for deoxidizing an Al—Nb—Ti alloy, which includes melting and holding an Al—Nb—Ti alloy containing from 50 to 75 mass % of Al, from 5 to 30 mass % of Nb, and 80 mass % or less in total of Al and Nb by a melting method using a water-cooled copper vessel in an atmosphere of 1.33 Pa to 2.67×10.sup.5 Pa at a temperature of 1,900 K or more, thereby decreasing an oxygen content thereof. The Al—Nb—Ti alloy is prepared using an alloy material formed of an aluminum material, a niobium material and a titanium material and containing oxygen in a total amount of 0.5 mass % or more.

Disclosed is a steel composition including specified ranges of Ni; Mo; Co; Mo+Co+Si+Mn+Cu+W+V+Nb+Zr+Ta+Cr+C; Co+Mo; Ni+Co+Mo; and traces of Al; Ti; N; Si; Mn; C; S; P; B; H; O; Cr; Cu; W; Zr; Ca; Mg; Nb; V; and Ta in specified ranges; the remainder being iron and impurities. The inclusion population, as observed by image analysis over a polished surface measuring 650 mm.sup.2 if hot-formed or hot-rolled; and measuring 800 mm.sup.2 if cold-rolled, does not contain non-metallic inclusions of diameter >10 μm, and, in the case of a hot-rolled sheet, does not contain more than four non-metallic inclusions of diameter 5-10 μm over 100 mm.sup.2, the observation being performed by image analysis over a polished surface measuring 650 mm.sup.2.

Disclosed is a steel composition including specified ranges of Ni; Mo; Co; Mo+Co+Si+Mn+Cu+W+V+Nb+Zr+Ta+Cr+C; Co+Mo; Ni+Co+Mo; and traces of Al; Ti; N; Si; Mn; C; S; P; B; H; O; Cr; Cu; W; Zr; Ca; Mg; Nb; V; and Ta in specified ranges; the remainder being iron and impurities. The inclusion population, as observed by image analysis over a polished surface measuring 650 mm.sup.2 if hot-formed or hot-rolled; and measuring 800 mm.sup.2 if cold-rolled, does not contain non-metallic inclusions of diameter >10 μm, and, in the case of a hot-rolled sheet, does not contain more than four non-metallic inclusions of diameter 5-10 μm over 100 mm.sup.2, the observation being performed by image analysis over a polished surface measuring 650 mm.sup.2.

Provided is a titanium cast product made of commercially pure titanium, the titanium cast product being produced by electron-beam remelting or plasma arc melting, comprising: a melted and resolidified layer in a range of 1 mm or more in depth at a surface serving as a surface to be rolled, the melted and resolidified layer being obtained by adding one or more kinds of β stabilizer elements to the surface and melting and resolidifying the surface. An average value of β stabilizer element(s) concentration in a range of within 1 mm in depth is higher than β stabilizer element(s) concentration in a base material by, in mass %, equal to or more than 0.08 mass % and equal to or less than 1.50 mass %. As the material containing the β stabilizer element, powder, a chip, wire, or foil is used. As means for melting a surface layer, electron-beam heating and plasma arc heating are used.

A method for deoxidizing a Ti—Al alloy includes melting and holding a Ti—Al alloy containing 40 mass % or more of Al by a melting method using a water-cooled copper vessel in an atmosphere of 1.33 Pa or more, thereby decreasing an oxygen content in the Ti—Al alloy. The Ti—Al alloy is manufactured using an alloy material composed of a titanium material and an aluminum material. The alloy material contains oxygen in a total amount of 0.1 mass % or more.

A method for deoxidizing a Ti—Al alloy includes melting and holding a Ti—Al alloy containing 40 mass % or more of Al by a melting method using a water-cooled copper vessel in an atmosphere of 1.33 Pa or more, thereby decreasing an oxygen content in the Ti—Al alloy. The Ti—Al alloy is manufactured using an alloy material composed of a titanium material and an aluminum material. The alloy material contains oxygen in a total amount of 0.1 mass % or more.