Patent classifications
C21D9/00
Personal ornament and method for producing personal ornament
A personal ornament has excellent corrosion resistance, in which predetermined chemical components are included, the remainder includes Fe and impurities, a structure contains austenite at 95% or more in area %, when a diameter of a circle having a smallest area capable of including one intermetallic compound inside is defined as a size of the intermetallic compound, the number of intermetallic compounds in which the size of the intermetallic compound is 150 μm or more is 0, and the number of intermetallic compounds in which the size is 13 μm or more and less than 150 μm is 3 or less, an average equivalent circle diameter of the austenite is 150 μm or less, and a PRE defined by the following formula (1) is 40 or more.
PRE=[Cr]+3.3[Mo]+16[N] (1)
CONTINUOUS HOT DIP GALVANIZING APPARATUS
A continuous hot-dip galvanizing apparatus has a vertical annealing furnace, one or more hearth rolls, a hot-dip galvanizing apparatus, an alloying line, and humidified gas supply ports. When the steel sheet having a Si content of 0.2 mass % or more is conveyed inside the annealing furnace, the humidified gas supply ports positioned in a latter part of the soaking zone supply the humidified gas to the soaking zone and the at least one dry gas supply port supplies the dry gas to the soaking zone. When the steel sheet having a Si content of less than 0.2 mass % is conveyed inside the annealing furnace, the plurality of the humidified gas supply ports do not supply the humidified gas to the soaking zone and the at least one dry gas supply port supplies the dry gas to the soaking zone.
Non-oriented electrical steel sheet and method of manufacturing stacked core using same
Provided are a non-oriented electrical steel sheet with which it is possible to improve steel sheet transferability even when punching is performed successively at high speed, and a method of manufacturing a stacked core using the same. The non-oriented electrical steel sheet contains, by mass percent, Si: 2.0 to 5.0%, Mn: 0.4 to 5.0%, Al≤3.0%, C: 0.0008 to 0.0100%, N≤0.0030%, S≤0.0030%, and Ti≤0.0060%, wherein the product of the contents of Mn and C is 0.004 to 0.05 mass %.sup.2, the yield strength in rolling direction is more than or equal to 600 MPa, and the Young's modulus is more than or equal to 200 GPa. In the method of manufacturing a stacked core, when manufacturing a stacked core using a progressive die, the steel sheet transfer speed V (m/s) satisfies expression (1). V: V.sub.MIN to V.sub.MAX (1) V.sub.MAX=( 1/25)√(t.sup.2×E×YS) (2) V.sub.MIN=( 1/25)√(t.sup.2×120000) (3) t: Steel sheet thickness (mm), E: Young's ratio (GPa), YS: Yield strength (MPa).
Construction machine bucket part and manufacturing method therefor
A construction machinery bucket part includes a body including a low alloy cast iron, and a wear resistant tip cast bonded to an end portion of the body and including a white cast iron. The construction machinery bucket part includes dissimilar materials, and has improved economic feasibility and wear resistance.
Construction machine bucket part and manufacturing method therefor
A construction machinery bucket part includes a body including a low alloy cast iron, and a wear resistant tip cast bonded to an end portion of the body and including a white cast iron. The construction machinery bucket part includes dissimilar materials, and has improved economic feasibility and wear resistance.
A METHOD FOR PRODUCING SPHEROIDIZED OR NON-LAMELLAR MICROSTRUCTURE STEELS
The present disclosure discloses a method for producing high strength hot rolled steel. The method includes casting a steel slab of a composition, comprising in weight %: carbon (C) of about 0.45 wt. %-1.2 wt. %, manganese (Mn) of about 0.0-1.0 wt. %, silicon (Si) of about 0.0-0.5 wt. %, niobium (Nb) up-to 0.03 wt. %, sulphur (S) up-to 0.05 wt. % of S, phosphorous (P) up-to 0.05 wt. %, nitrogen (N) 0.002 wt. %-0.012 wt. % and balance being Iron (Fe) optionally along with incidental elements. The method also involves, heating, hot rolling, cooling, coiling the steel and retaining the steel at an ambient temperature to produce high strength hot rolled steel with 75-95% spheroid microstructure and 5-25% pearlite microstructure.
Steel for nitrocarburizing and nitrocarburized component, and methods of producing same
Provided is a steel for nitrocarburizing that ensures mechanical workability before nitrocarburizing treatment. A steel for nitrocarburizing comprises: a chemical composition containing, in mass %, C: ≥0.02% and <0.15%, Si: ≤0.30%, Mn: 1.5-2.5%, P: ≤0.025%, S: ≤0.06%, Cr: 0.5-2.0%, Mo: 0.005-0.2%, V: 0.02-0.20%, Nb: 0.003-0.20%, Al: >0.020% and ≤1.0%, Ti: >0.0050% and ≤0.015%, N: ≤0.0200%, Sb: 0.0030-0.010%, with a balance being Fe and inevitable impurities, satisfying Expression (1) or (2); and a steel microstructure where an area ratio of bainite phase is >50%, a prior austenite grain size is ≤100 μm, ≥300/μm.sup.2 Ti precipitates with an equivalent circular particle size of ≤30 nm disperse, Sb segregates to prior austenite grain boundaries.
Steel for nitrocarburizing and nitrocarburized component, and methods of producing same
Provided is a steel for nitrocarburizing that ensures mechanical workability before nitrocarburizing treatment. A steel for nitrocarburizing comprises: a chemical composition containing, in mass %, C: ≥0.02% and <0.15%, Si: ≤0.30%, Mn: 1.5-2.5%, P: ≤0.025%, S: ≤0.06%, Cr: 0.5-2.0%, Mo: 0.005-0.2%, V: 0.02-0.20%, Nb: 0.003-0.20%, Al: >0.020% and ≤1.0%, Ti: >0.0050% and ≤0.015%, N: ≤0.0200%, Sb: 0.0030-0.010%, with a balance being Fe and inevitable impurities, satisfying Expression (1) or (2); and a steel microstructure where an area ratio of bainite phase is >50%, a prior austenite grain size is ≤100 μm, ≥300/μm.sup.2 Ti precipitates with an equivalent circular particle size of ≤30 nm disperse, Sb segregates to prior austenite grain boundaries.
Free-cutting copper alloy and method for producing free-cutting copper alloy
This free-cutting copper alloy contains Cu: more than 57.5% but less than 64.5%, Si: more than 0.20% but less than 1.20%, Pb: more than 0.001% but less than 0.20%, Bi: more than 0.10% but less than 1.00%, and P: more than 0.001% but less than 0.20%, with the balance being Zn and unavoidable impurities, wherein the total amount of Fe, Mn, Co and Cr is less than 0.45%, the total amount of Sn and Al is less than 0.45%, relationships of 56.3≤f1=[Cu]−4.8×[Si]+0.5×[Pb]+0.5×[Bi]−0.5×[P]≤59.5 and 0.12≤f2=[Pb]+[Bi]<1.0 are satisfied.
Free-cutting copper alloy and method for producing free-cutting copper alloy
This free-cutting copper alloy contains Cu: more than 57.5% but less than 64.5%, Si: more than 0.20% but less than 1.20%, Pb: more than 0.001% but less than 0.20%, Bi: more than 0.10% but less than 1.00%, and P: more than 0.001% but less than 0.20%, with the balance being Zn and unavoidable impurities, wherein the total amount of Fe, Mn, Co and Cr is less than 0.45%, the total amount of Sn and Al is less than 0.45%, relationships of 56.3≤f1=[Cu]−4.8×[Si]+0.5×[Pb]+0.5×[Bi]−0.5×[P]≤59.5 and 0.12≤f2=[Pb]+[Bi]<1.0 are satisfied.