The present disclosure relates to wear-resistant steel comprising, by weight, carbon (C): 0.19 to 0.28%, silicon (Si): 0.1 to 0.7%, manganese (Mn): 0.6 to 1.6%, phosphorus (P): 0.05% or less, sulfur (S): 0.02% or less, aluminum (Al): 0.07% or less, chromium (Cr): 0.01 to 0.5%, nickel (Ni): 0.01 to 3.0%, copper (Cu): 0.01 to 1.5%, molybdenum (Mo): 0.01 to 0.5%, boron (B): 50 ppm or less, and cobalt (Co): 0.02% or less, further comprising one or more selected from the group consisting of titanium (Ti): 0.02% or less, niobium (Nb): 0.05% or less, vanadium (V): 0.05% or less, and calcium (Ca): 2 to 100 ppm, and comprising a remainder of iron (Fe) and other unavoidable impurities, wherein C, Ni, and Cu satisfy the following relationship 1, wherein a microstructure includes 97 area % or more of martensite:
C×Ni×Cu≥0.05.  [Relationship 1]
.

A steel consists of, in mass %, C: 0.25 to 0.45%, Si: 0.10 to 0.50%, Mn: 0.40 to 0.70%, P: 0.015% or less, S: 0.005% or less, Cr: 0.80 to 1.50%, Mo: 0.17 to 0.30%, V: 0.24 to 0.40%, Al: 0.005 to 0.100%, N: 0.0300% or less, O: 0.0015% or less, and the balance being Fe and impurities, and satisfies Formula (1) to Formula (4) described in the present specification, wherein: its microstructure is composed of ferrite and pearlite having a total area fraction of 5.0 to 100.0%, and a hard phase having a total area fraction of 0 to 95.0%; a proportion of a total area of CaO—CaS—MgO—Al.sub.2O.sub.3 composite oxides with respect to a total area of oxides in the steel is 30.0% or more; and a number density of oxides having an equivalent circle diameter of 20.0 μm or more is 15.0 pieces/mm.sup.2 or less.

The present invention relates to the technical field of material processing and provides a method for making a metal material composite, including: contacting a first surface of a first plate with a second surface of a second plate; placing the first plate and the second plate in a recess in a circumferential direction of a first roller such that a third surface of the second plate contacts a bottom wall of the recess in a circumferential, the third surface being opposite the second surface, the first plate having a greater hardness than the second plate; and controlling a first roller and a second roller to rotate, thereby rolling to combine the first plate and the second plate into a composite plate, where a fourth surface of the first plate contacts a surface of the second roller and the fourth surface is opposite the first surface during the rolling. According to the method for making a metal material composite in the present invention, flashings and burr on the side edges of a composite plate are avoided by placing the first plate and the second plate in a recess for machining.

Steel for glass lining, comprising the following chemical elements in mass percent: C: 0.015-0.060%, Si: 0.01-0.50%, Mn: 0.20-1.5%, P: 0.005-0.10%, Al: 0.010-0.070%, Ti: 0.10-0.30%, and the balance of Fe and other inevitable impurities. The microstructure of the steel for glass lining is a ferrite or a combination of a ferrite and a cementite. In addition, also disclosed is a production method for steel for glass lining, comprising the steps of (1) smelting, refining, and continuous casting to obtain a slab; (2) heating, the heating temperature being 1050-1250° C.; (3) hot rolling, the final temperature of hot rolling being controlled to be 800-920° C.; (4) cooling; and (5) thermal treatment. The steel for glass lining has excellent machinability and low temperature toughness, and also has excellent lining performance.

A steel sheet for hot stamping includes an amount of 0.17 wt % to 0.25 wt % of carbon (C), an amount of 0.3 wt % to 1.0 wt % of silicon, an amount of 0.6 wt % to 1.0 wt % of manganese (Mn), an amount of 0.02 wt % or less of phosphorus (P), an amount of 0.01 wt % or less of sulfur (S), an amount of 0.1 wt % to 1.0 wt % of aluminum (Al), an amount of 0.001 wt % to 0.005 wt % of boron (B), an amount of 0.01 wt % to 0.1 wt % of titanium (Ti), an amount of 0.02 wt % to 0.06 wt % of niobium (Nb), an amount of 0.3 wt % to 1.0 wt % of a sum of at least one of chromium (Cr), nickel (Ni), and molybdenum (Mo), and the balance of iron (Fe) and other unavoidable impurities; and also a microstructure including ferrite and pearlite.

A nickel-free LPG marine steel plate and a manufacturing method therefor belong to the technical field of high-strength structural steels; the steel plate consists of the following chemical components by mass percentage: 0.18 to 0.24% of C, 0.10 to 0.19% of Si, 16.1 to 18.9% of Mn, less than or equal to 0.012% of P, 0.15 to 0.35% of Mo, 0.10 to 0.25% of RE, and the balance of Fe and inevitable impurities; the steel plate has a yield strength of ≥410 MPa and an impact absorption work of ≥66 J at 150° C., has good low-temperature mechanical properties, can replace 5Ni and 9Ni-based steel, and is used for constructing an LPG storage tank and a relevant structural member at low costs.

Disclosed is 500-MPa low-yield-ratio weather-resistant bridge steel and a manufacturing method therefor; the weather-resistant bridge steel includes the following components in percentage by mass: C: 0.04%-0.09%, Si: 0.15%-0.30%, Mn: 1.40%-1.50%, P: 0.009%-0.015%, S: ≤0.002%, Nb: 0.020%-0.050%, Ti: 0.010%-0.020%, V: 0.010%-0.030%, Cu: 0.30%-0.40%, Ni: 0.30%-0.45%, Cr: 0.45%-0.60%, Mo: 0.08%-0.15%, Alt: 0.02%-0.04%, and the balance Fe and inevitable impurities; through scientific component designing and a matched manufacturing method combining controlled rolling and cooling and tempering, the weather-resistant bridge steel has a low yield ratio, high low-temperature toughness and high elongation.

Provided is a free-cutting steel that, despites not containing Pb, has machinability by cutting higher than or equal to that of a low carbon sulfur-lead composite free-cutting steel. A free-cutting steel comprises: a chemical composition that contains, in mass %, C: less than 0.09%, Mn: 0.50% to 1.50%, S: 0.250% to 0.600%, O: more than 0.010% and 0.050% or less, and Cr: 0.50% to 1.50%, with a balance consisting of Fe and inevitable impurities, and in which a A value defined by the following formula (1) is 6.0 to 18.0, and a steel microstructure in which at least 500 particles/mm.sup.2 of sulfide of less than 1 μm in equivalent circle diameter and at least 2000 particles/mm.sup.2 of sulfide of 1 μm to 5 μm in equivalent circle diameter are distributed.

A slab library for separate storage of cold blanks and hot blanks of heavy plates and heating furnace layout, and a furnace loading method are provided. The slab library and heating furnace layout comprises: 1# slab library and 2# slab library span, i.e. feeding span, arranged side by side; continuous casting blank delivery roller way connected to the continuous casting process arranged at the inlet of the 2# slab library span; heating furnace span arranged at the outlet of the 2# slab library span, wherein more than two heating furnaces are arranged in the heating furnace span, and arranged side by side at the outlet of the 2# slab library span; slab preparatory library span, which is across the inlets of the 1# slab library span and the 2# slab library span; span-crossing traverse trolley roller way, which is across the cold blank zones of the 1# slab library span and the 2# slab library span, and the heating furnace span; span-crossing roller way, which is across the slab preparatory library span and the 1# slab library span; and, feeding roller way, arranged between the 2# slab library span and the heating furnace span, and across the hot blank zone and the cold blank zone of the 2# slab library span and the two ends of the heating furnace span, wherein the feeding roller way has a structure for delivery in two directions.

A thick-walled, high-toughness, high-strength steel plate manufactured from steel having a particular composition and casted under conditions where the cooling rate of a surface during solidification is 1° C./s or less. The surface of the steel plate has a toughness (vE-40) of 70 J or more, and the steel plate has a thickness of 100 mm or more.