摘要:
A method is proved for hot pressing hot rolled steel sheet, cold rolled steel sheet, Al-based plated steel sheet or Zn-based plated steel sheet, where the hot pressed sheet can exhibit a strength of at least about 1200 Mpa, and my be prevented from exhibiting hydrogen embrittlement. The steel sheet may include between about 0.05 to 0.5 wt % C, and/or it may be plated with an Al-based or Zn-based plating material. The steel sheet may be heating to a temperature greater than an Ac3 temperature and not more than about 1100° C. before pressing. An atmosphere can be provided during heating which contains not more than about 6 vol % of hydrogen and a dew point of not more than about 10° C. The exemplary methods may be used to form high strength parts which may be used, e.g., in automobiles.
摘要:
The present invention provides a method of hot pressing using hot rolled and cold rolled steel sheet or Al-based plated steel sheet or Zn-based plated steel sheet enabling a strength of at least 1200 MPa to be obtained after high temperature forming and with extremely little possibility of hydrogen embrittlement and such hot pressed parts, that is, a method of hot pressing a high strength automobile parts comprising using steel sheet containing as steel compositions by wt % C:0.05 to 0.5% or steel sheet plated mainly with Al or Zn to produce automobile members by hot pressing during which making the heating temperature before pressing Ac3 or more to 1100° C. or less, making the hydrogen concentration in the heating atmosphere 6 vol % or less, and making the dew point 10° C. or less and such hot pressed parts.
摘要:
The present invention provides an electric resistance welded steel pipe for a hollow stabilizer excellent in workability, which steel pipe contains, in mass, 0.20 to 0.35% of C, 0.10 to 0.50% of Si, 0.30 to 1.00% of Mn, 0.01 to 0.10% of Al, 0.10 to 1.00% of Cr, 0.005 to 1.00% of Mo, 0.001 to 0.02% of Ti, 0.0005 to 0.0050% of B and 0.0010 to 0.0100% of N, satisfying the expression N/14
摘要:
A high-nitrogen ferritic heat-resisting steel with high vanadium content comprises, in weight percent, 0.01-0.30% C, 0.02-0.80% Si, 0.20-1.00% Mn, 8.00-13.00% Cr, 0.005-1.00% Mo, 0.20-1.50% W, 0.30-2.00% V, and 0.10-0.50% N and being controlled to include less than 0.020% Nb, the balance being Fe and unavoidable impurities. A method of producing the steel comprises melting and equilibrating the steel components in an atmosphere of a mixed gas of a prescribed nitrogen partial pressure or nitrogen gas and thereafter casting or solidifying the resulting melt in an atmosphere controlled to have a total pressure of not less than 2.77 bar and a nitrogen partial pressure of not less than 1.0 bar, with the relationship between the nitrogen partial pressure p and the total pressure P beingP>2.77pthereby obtaining sound ingot free of blowholes.
摘要:
A martensitic heat-resisting steel comprises, in terms of % by mass, 0.01 to 0.30% of C, 0.02 of 0.80% of Si, 0.20 to 1.00% of Mn, 5.00 to 18.00% of Cr, 0.005 to 1.00% of Mo, 0.20 to 3.50% of W, 0.02 to 1.00% of V, 0.01 to 0.50% of Nb, 0.01 to 0.25% of N, and at least one element selected from the group consisting of Ti, Zr, Ta and Hf in an amount of 0.005 to 2.0% for each of the elements, the volume of (Ti %+Zr %+Ta %+Hf %) in the metal component M of M.sub.23 C.sub.6 type carbides therein being from 5 to 65%. The heat-resisting steel is produced by a process comprising the steps ofadding Ti, Zr, Ta and Hf to a molten steel having chemical components as mentioned above, during the period from 10 minutes before completion of refining to completion of refining, casting said molten steel, working the resulting casting, solution treating said worked product, subjecting said worked product to temporary cooling stop at a temperature from 950.degree. to 1,000.degree. C. in the course of cooling said hot worked product, and holding said worked product at the temperature for 5 to 60 minutes. The heat-resisting steel is excellent in HAZ-softening resistance, and exhibits a high creep strength at high temperature of at least 550.degree. C.
摘要:
A high-nitrogen ferritic heat-resisting steel with high niobium content comprises, in weight per cent, 0.01-0.30% C, 0.02-0.80% Si, 0.20-1.00% Mn, 8.00-13.00% Cr, 0.005-1.00% Mo, 0.20-1.50% W, 0.05-1.00% V, over 0.12 up to 2.00% Nb and 0.10-0.50%N, the balance being Fe and unavoidable impurities. A method of producing the steel comprises melting and equilibrating the steel components in an atmosphere of a mixed gas of a prescribed nitrogen partial pressure or nitrogen gas and thereafter casting or solidifying the resulting melt in an atmosphere controlled to have a total pressure of not less than 2.5 bar and a nitrogen partial pressure of not less than 1.0 bar, with the relationship between the nitrogen partial pressure p and the total pressure P beingP>2.5p.
摘要:
A martensitic heat resistant steel is provided which has improved high temperature creep strength, contains Co and, at a temperature of 600.degree. C. or above, does not form an intermetallic compound substantially having a composition of Cr.sub.40 Mo.sub.20 Co.sub.20 W.sub.10 C.sub.2 --Fe. In a heat-resistant steel, containing not less than 8% of Cr, with Co, Mo, and W being simultaneously added thereto, a combination of the addition of a very small of Mg, Ba, Ca, Y, Ce, La and the like, with the addition of a minor amount of Ti and Zr, inhibits the precipitation of an intermetallic compound substantially having a composition of Cr.sub.40 Mo.sub.20 Co.sub.20 W.sub.10 C.sub.2 --Fe, thereby ensuring high temperature creep strength.