Described herein are thin metal strips having hot rolled exterior side surfaces characterized as being primarily or substantially free of all prior austenite grain boundaries, or at least primarily or substantially free of all prior austenite grain boundaries, and including elongated surface structure. As a result, because the prior austenite grain boundaries are not primarily or substantially present, all such prior austenite grain boundaries are not susceptible to grain boundary etching due to acid etching or pickling. In particular examples, the thin metal strips undergo hot rolling performed with a coefficient of friction equal to or greater than 0.20 with or without use of lubrication.

Provided is a continuous casting method of steel that prevents a solidification completion position from being changed even when a drawing speed V of a cast slab is changed. The method includes drawing a cast slab by setting a drawing speed V0 while spraying cooling water to the cast slab at a cooling water spray amount W0 [kg/ton-cast slab]. Then, changing the drawing speed to the speed V1 while spraying cooling water to the cast slab at a cooling water spray amount W1 [kg/ton-cast slab]. The method further includes spraying cooling water to the cast slab at a cooling water spray amount Wt [kg/ton-cast slab] during a period of time t that is obtained by dividing a target length Lt by the drawing speed V0. The water spray amount Wt satisfying either formula (1): Wt<W1 under a condition of V1<V0, or formula (2): Wt>W1 under a condition of V1>V0.

In exemplary implementations of this invention, an actuated fabricator deposits structural elements (e.g., tensile structural elements) in a 3D pattern over large displacements. The fabricator is supported by at least three elongated support members. It includes onboard actuators that translate the fabricator relative to the ends of the support members. The fabricator is configured, by actuating different translations along different support members, to translate itself throughout a 3D volume. In some implementations, each of the actuators use fusible material to fuse metal tapes together, edge-to-edge, to form a hollow structure that can be shortened or lengthened.

An apparatus for continuous casting metal strip reducing snake eggs comprising a pair of counter rotating casting rolls, each roll less than 800 millimeters in diameter and positioned to form a nip there between through which thin strip can be cast; a metal delivery system disposed above the nip and capable of discharging molten metal to form a casting pool supported on the rolls; a pair of side dam holders and a pair of side dams assembled adjacent each end portion of the rolls, each side dam holder tapered along edge portions to dovetail with an adjacent side dam, and each side dam adapted to confine the casting pool of molten metal supported on casting surfaces of the rolls; an oscillation mechanism adapted to cause lateral oscillation of each side dam and side dam holder at a frequency 2-50 hertz and with an amplitude 100-2000 m during a casting campaign.

An abrasion-resistant steel plate comprises: a specific chemical composition; and a microstructure in which a volume fraction of martensite at a depth of 1 mm from a surface of the abrasion-resistant steel plate is 90% or more, and a prior austenite grain size in a plate thickness central part at the mid-thickness of the abrasion-resistant steel plate is 80 m or less, wherein hardness at a depth of 1 mm from the surface of the abrasion-resistant steel plate is 460 to 590 HBW 10/3000 in Brinell hardness, and a concentration [Mn] of Mn in mass % and a concentration [P] of P in mass % in a plate thickness central segregation area satisfy 0.04[Mn]+[P]<0.50.

A high-carbon hot rolled steel sheet with excellent hardenability and small in-plane anisotropy, and a method for manufacturing the steel sheet are provided. The steel sheet has a chemical composition including, by mass %, C: 0.20 to 0.48%, Si: not more than 0.1%, Mn: not more than 0.5%, P: not more than 0.03%, S: not more than 0.01%, sol. Al: not more than 0.10%, N: not more than 0.005% and B: 0.0005 to 0.0050%, the balance including Fe and inevitable impurities. The steel sheet includes a microstructure containing ferrite and cementite. The cementite has an average grain size of not more than 1.0 m. The steel sheet has an in-plane anisotropy of r value, r, of not more than 0.1 in absolute value.

A hot-rolled steel sheet for a generator rim contains a structure containing a ferrite phase with an areal ratio of 95% or more in which precipitates containing Ti and V whose average grain diameter is less than 10 nm are precipitated in crystal grains of the ferrite phase. The ferrite phase has an average crystal grain diameter within the range of 2 m or more and less than 10 m. The hot-rolled steel sheet for a generator rim has strength with a yield strength YS in a rolling direction of 700 MPa or more and electromagnetic properties with a magnetic flux density B.sub.50 of 1.5 T or more and a magnetic flux density B.sub.100 of 1.6 T or more.

A continuous casting and rolling apparatus according to one embodiment of the present invention comprises: a continuous casting apparatus for producing a steel sheet; a roller, linked to the continuous casting apparatus, for receiving the steel sheet; and a push heat unit, connected to the continuous casting apparatus and/or the roller, for selectively carrying outing heating work or removal work with respect to a portion of the steel sheet. Also, a continuous casting and rolling method according to another embodiment of the present invention may comprise: a continuous casting step for producing a steel sheet; and a selective performance step for selectively carrying out heating work or removal work with respect to a portion of the steel sheet.

An abrasion-resistant steel plate comprises: a chemical composition containing, in mass %, C: 0.20% to 0.45%, Si: 0.01% to 1.0%, Mn: 0.3% to 2.5%, P: 0.020% or less, S: 0.01% or less, Cr: 0.01% to 2.0%, Ti: 0.10% to 1.00%, B: 0.0001% to 0.0100% , Al: 0.1% or less, N: 0.01% or less, and a balance consisting of Fe and inevitable impurities; and a microstructure in which a volume fraction of martensite is 90% or more, and a prior austenite grain size is 80 m or less, wherein a number density of TiC precipitate having a size of 0.5 m or more is 400 particles/mm.sup.2 or more, and a Mn content [Mn] and a P content [P] in a plate thickness central segregation area satisfy 0.04[Mn]+[P]<0.50.

An abrasion-resistant steel plate comprises: a specific chemical composition; and a microstructure in which a volume fraction of martensite at a depth of 1 mm from a surface of the abrasion-resistant steel plate is 90% or more, and a prior austenite grain size at the mid-thickness of the abrasion-resistant steel plate is 80 m or less, wherein hardness at a depth of 1 mm from the surface of the abrasion-resistant steel plate is 360 to 490 HBW 10/3000 in Brinell hardness, and a concentration [Mn] of Mn in mass % and a concentration [P] of P in mass % in a plate thickness central segregation area satisfy 0.04[Mn]+[P]<0.55.