A centrifugally cast composite roll for hot rolling comprising an outer layer made of an Fe-based alloy having a chemical composition comprising by mass 2.6-3.6% of C, 0.1-3% of Si, 0.3-2% of Mn, 2.3-5.5% of Ni, 0.5-3.2% of Cr, 0.3-1.6% of Mo, 1.8-3.4% of V, and 0.7-2.4% of Nb, 1.4 ≤V/Nb ≤2.7, a V equivalent (Veq=V+0.55 Nb) being 2.60-4% by mass, and the balance being Fe and impurities, and an inner layer made of an iron-based alloy and integrally fused to the outer layer.

A tempering-free wear-resistant hot rolled strip, includes components in percentage by weight: 0.08-0.22% of C, 0.1-0.55% of Si, 0.8-1.5% of Mn, less than or equal to 0.012% of P, less than or equal to 0.005% of S, 0.01-0.055% of Als, 0.005-0.019% of Ti, and less than or equal to 0.007% of N. A method for producing the same includes: desulfurizing molten iron, smelting desulfurized molten iron, and casting into a blank; heating the casting blank; performing rough rolling; performing finish rolling; performing rapid cooling; performing coiling; and performing conventional temper rolling. According to the present disclosure, on the premise that the tensile strength of a steel plate is greater than or equal to 1100 MPa and the elongation is greater than or equal to 12%, the steel plate has a surface Brinell hardness of 330-390 and a core hardness that is 95% or above of the surface hardness.

The present invention provides a microalloyed steel mechanical property prediction method based on globally additive model, including the following steps: determining some influencing factors of the microalloyed steel mechanical property prediction model; calculating the components and contents of carbonitride precipitation in a microalloyed steel rolling process; expressing the microalloyed steel mechanical property prediction model as an additive form of several submodels according to generalized additive model; estimating the microalloyed steel mechanical property prediction model; and verifying reliability of the submodels. The microalloyed steel property prediction models obtained in the foregoing solution have advantages such as high prediction precision and a wide adaptation range, and may be used for design of new products and steel grade component optimization, so as to reduce the quantity of physical tests, shorten the product research and development cycle, and reduce costs.

A Si/Mn ratio of steel material components of a base material is not less than 0.27 nor more than 0.90 in mass ratio, an internal oxide layer having a thickness of not less than 1 μm nor more than 30 μm is provided right below an oxide scale of a steel sheet surface layer portion, and regarding the internal oxide layer, an internal oxide in a crystal grain of the internal oxide layer is an oxide containing Si and having a thickness of not less than 10 nm nor more than 200 nm in a crystal grain in a range of greater than 0% and 30% or less of a thickness of the internal oxide layer from an interface between the internal oxide layer and base iron toward a direction of the surface layer oxide scale, one or more branches of the internal oxide exist in a cross section of 1 μm×1 μm square, and in any crystal grain boundary having a length of 1 μm, one or more of the internal oxides in the crystal grain are connected to an internal oxide of the crystal grain boundary to form a net-like structure.

Disclosed are alloys for anodized-quality aluminum sheets with improved surface quality, and methods for making these sheets. The alloys are designed to minimize the formation of cathodic intermetallic particles that result in surface streaks of anodized sheet products formed from the alloys. Further, the alloys allow the incorporation of recycled scrap aluminum in anodized-quality sheets.

Provided is a titanium casting product made of titanium alloy, the titanium casting product being produced by electron-beam remelting or plasma arc remelting, 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 concentration in a range of within 1 mm in depth is higher than β stabilizer element 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.

To achieve a substantially uniform microstructure across a continuously cast thin metal strip, it is beneficial to cool a width of the strip to a substantially constant temperature before further cooling the strip to reach any desired phase transformation temperature. Accordingly, methods of continuously casting a thin metal strip may include moving the thin strip to a cooling section, the cooling section having a plurality of coolant discharge ports configured to discharge a flow of coolant along the thin strip; initially sensing the temperature of the thin strip to determine a temperature distribution across the width of the thin strip, and producing a sensor signal corresponding to a sensed temperature at each of the first plurality of locations; and individually controlling the cooling across a width of the thin strip by way of the plurality coolant discharge ports in each zone of a first row using the determined temperature distribution.

Provided is a wire rod having enhanced strength and impact toughness comprising, by wt %, carbon (C): 0.05% to 0.15%, silicon (Si): 0.2% or less, manganese (Mn): 3.0% to 4.0%, phosphorus (P): 0.020% or less, sulfur (5):0.020% or less, boron (B): 0.0010% to 0.0030%, titanium (Ti): 0.010% to 0.030%, nitrogen (N): 0.0050% or less, aluminum (Al): 0.010% to 0.050%, iron (Fe) as a residual component thereof, and other unavoidable impurities. A microstructure includes bainitic ferrite in an area fraction of 90% or more, and a martensite/austenite (M/A) constituent as a residual component thereof.

A steel product bent by heating to 600° C. or more, specifically a heat treated steel product having high strength and excellent chemical conversion coating ability which has scale with FeO content of 90% or more, having a thickness of 1 μm or less on the surface.

Disclosed is a Grade 550 MPa high temperature-resistant pipeline steel, the chemical elements, in mass percentage, being: 0.061%≦C≦0.120%, 1.70%≦Mn≦2.20%, 0.15%≦Mo≦0.39%, 0.15%≦Cu≦0.30%, 0.15%≦Ni≦0.50%, 0.035%≦Nb≦0.080%, 0.005%≦V≦0.054%, 0.005%≦Ti≦0.030%, 0.015%≦Al≦0.040%, 0.005%≦Ca≦0.035%, and the balance being Fe and unavoidable impurities. Also disclosed is a manufacturing method of the Grade 550 MPa high temperature-resistant pipeline steel, comprising the steps of: smelting, casting, slab heating, rough rolling, finish rolling, controlled cooling, and air cooling to room temperature. The pipeline steel has an excellent mechanical property under a high temperature.