A non-oriented electrical steel sheet according to an embodiment of the present invention includes, in wt %, Si: 1.5% or less, C: 0.01% or less (excluding 0%), Mn: 0.03 to 3%, P: 0.01 to 0.2%, S: 0.001 to 0.02%, Al: 0.01% or less (excluding 0%), N: 0.005% or less (excluding 0%), Cu: 0.02 to 0.3%, 0.0001 to 0.005 wt % of Ca and Mg either alone or in total, 0.001 to 0.2 wt % of Sb and Sn either alone or in total, and a balance of Fe and inevitable impurities.

Disclosed are a wire rod and a component, for cold forging, each having excellent delayed fracture resistance characteristics and applicable to high-strength bolts and the like and a manufacturing method therefor.

According to an embodiment, a heat-treated component having excellent delayed fracture resistance characteristics includes, in percent by weight (wt %), 0.3 to 0.5% of C, 0.01 to 0.3% of Si, 0.3 to 1.0% of Mn, at least two types selected from the group consisting of 0.3 to 1.5% of Cr, 0.3 to 1.5% of Mo, and 0.01 to 0.4% of V, and the balance being Fe and other impurities, includes, as a microstructure, a tempered martensite phase in an area fraction of 95% or more, and includes V-based carbides having a diameter of 300 nm or less at 10/100 μm.sup.2 or more.

A hot-rolled steel sheet for non-oriented electrical steel sheets includes, by mass %: C: 0.0010% to 0.0050%; Si: 1.90% to 3.50%; Al: 0.10% to 3.00%; Mn: 0.05% to 2.00%; P: 0.100% or less; S: 0.005% or less; N: 0.0040% or less; B: 0.0060% or less; Sn: 0% to 0.50%; Sb: 0% to 0.50%; Cu: 0% to 0.50%; REM: 0% to 0.0400%; Ca: 0% to 0.0400%; Mg: 0% to 0.0400%; and a remainder including Fe and impurities, in which a hardness H.sub.D of a deformed structure of a thickness middle portion (½t position) in a sheet width direction end portion of the hot-rolled steel sheet for non-oriented electrical steel sheets is Hv 220 or less.

A cold rolled and annealed steel sheet includes by weight: 0.6≤C≤1.3%, 15.0≤Mn≤35%, 5≤Al≤15%, Si≤2.40%, S≤0.03%, P≤0.1%, N≤0.1%, possibly one or more optional elements chosen among Ni, Cr and Cu in an respective amount of up to 4.0%, up to 3.0% and up to 3.0% and possibly one or more elements chosen among B, Ta, Zr, Nb, V, Ti, Mo, and W in a cumulated amount of up to 2.0%, the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration, the microstructure of the sheet including optionally up to 3% of kappa carbides, optionally up to 10.0% of granular ferrite, the remainder being made of austenite, the average grain size and average aspect ratio of the austenite being respectively below 6 μm and comprised between 1.5 and 6 and the average grain size and average aspect ratio of the ferrite, when present, being respectively below 5 μm and below 3.0.

The present invention relates to a method for producing an article out of a maraging steel, wherein the article is successively subjected to a solution annealing and heat treatment, wherein the steel has the following composition in Wt.-%: C=0.01-0.05 Si=0.4-0.8 Mn=0.1-0.5 Cr=12.0-13.0 Ni=9.5-10.5 Mo=0.5-1.5 Ti=0.5-1.5 Al=0.5-1.5 Cu=0.0-0.05

Residual iron and smelting-induced impurities.

A method for producing an austenitic heat resistant steel in which a difference between a content of Nb and an amount of Nb analyzed as extraction residues satisfies [0.170≤Nb−Nb.sub.ER≤0.480], the method including: a forming step of machining and forming a steel having a predetermined chemical composition into a product shape; a solution heat treatment step of performing, after the forming step, heat treatment under conditions including a heat treatment temperature satisfying [−250Nb+1200≤T≤−100Nb+1290] and a soaking time satisfying [405−0.3T≤t≤2475−1.5T]; and a cooling step of performing cooling after the solution heat treatment step.

The present invention relates to an additive manufacturing wire, containing, in terms of % by mass, 0%<Si≤2.0%, 0%<Mn≤6.0%, 3.0%≤Ni≤15.0%, 20.0%≤Cr≤30.0%, 1.0%≤Mo≤5.0%, 0%<N≤0.50%, with a balance being Fe and unavoidable impurities, in which C≤0.10% is satisfied, and 27<A<67 is satisfied, when Cr.sub.eq is defined as Cr+Mo+1.5Si+0.5(Nb+W)+2(Ti+Al), Ni.sub.eq is defined as Ni+30C+20N+0.5(Mn+Cu+Co), and A is defined as −16.2+6.3Cr.sub.eq−9.3Ni.sub.eq, here, in the definition of Cr.sub.eq and Ni.sub.eq, each element symbol indicates a content of the each element in units of % by mass.

An inductive hardening system for hardening a component includes a holding unit for holding the component, an induction coil configured to induce an electrical current in the component to heat the component, and a control unit configured to control the induction coil to produce a first amount of heat per unit area in the component until a predetermined temperature is reached and/or a predetermined time is elapsed and after the predetermined temperature is reached and/or the predetermined time is elapsed, to control the induction coil to produce a second amount of heat per unit area in the component, the second amount of heat being from 3% to 80% of the first amount of heat.

An essentially lead free steel having improved machinability while reducing or eliminating lead (except for trace impurities) and without detriment of the material properties of the steel. The properties of the lead free steel are dependent on both the composition and method of manufacture. The improved lead free steel has, in percent by weight (wt-%): Carbon: 0.39-0.43%; Manganese: 0.75-1.00%; Silicon: 0.15-0.35%; Chromium: 0.80-1.05%; Molybdenum: 0.15-0.25%; at least one of Tellurium: 0.003-0.090 wt-%, Selenium: 0.080-0.2 wt-%, Sulfur: 0.065-0.09% wt-%, and Bismuth: 0.03-0.1 wt-%; and the balance being Fe and normally occurring scrap steel impurities. The hot-rolled lead-free steel product is subjected to a heat treatment at a first temperature for a first duration, at a second temperature for a second duration that is less than the first temperature, at a third temperature for a third time period that is greater than the second temperature, and subsequently cooling the steel product.

Provided is a stainless steel sheet having a predetermined chemical composition, in which a total volume fraction of Cr-based carbides with a grain size of 2.0 μm or more is 10% or less.