摘要:
Steel is obtained which comprises by wt %, C: 0.001-0.025%, Si: not more than 0.60%, Mn: 0.10-3.00%, P: 0.005-0.030%, S: not more than 0.01%, Al: not more than 0.10%, Cu: 0.1-1.5%, Ni: 0.1-6.0%, B: 0.0001-0.0050%, and the balance being Fe and inevitable impurities; since the steel contains C and P in small contents, stable amorphous rusts are formed on the surface thereof at an early stage; and steel simultaneously realizes excellent weather resistance, material weldability and toughness particularly in an environment such as a seashore district and the like where salt is present in a large amount.
摘要:
The invention provides a steel product having superior weathering which is coated with a rust layer containing 50 or more weight % of non-crystalline rust, a method of producing the steel product, and a method of forming weathering protective rust on a material surface of the steel product. A material of a steel product is placed in an atmosphere in which the dew point is kept constant and the temperature of the steel product material is repeatedly varied between a temperature range of 5.degree. C. or more higher than the dew point and a temperature range of 5.degree. C. or more lower than the dew point. Weathering protective rust is thereby formed on the material surface of the steel product and a steel product having superior weathering is obtained. Preferably, the atmosphere contains 15 to 50 volume % of oxygen gas, and the temperature of the steel product is varied at a rising rate of 0.1 to 2.degree. C./minute and a lowering rate of 0.01 to 2.degree. C./minute. Alternatively, a desired steel product can also be obtained by placing a material of the steel product in an atmosphere containing 15 to 50 volume % of oxygen gas, keeping constant the dew point in the atmosphere, and keeping the temperature of the steel product material in the atmosphere at a certain value in a temperature range between a temperature 5.degree. C. lower than the dew point and a temperature 20.degree. C. lower than the dew point; or by placing a material of the steel product in an atmosphere containing 15 to 50 volume % of oxygen gas, and forming and keeping a water film with a thickness not more than 500 .mu.m but not less than 50 .mu.m on a material surface of the steel product.
摘要:
A steel material excellent in weathering resistance by defining the chemical ingredients in the steel each to a predetermined range and setting an ingredient parameter formula in accordance with the working circumstance thereby reducing the flow rust and, particularly, forming stable rust with good protective property even in a salty circumstance such as in coast districts is provided. Further, also considering the amount of A type inclusions and B type inclusions according to JIS G 0555, a steel material of excellent earthquake proofness and weathering proofness also including weld heat affect zone is provided.
摘要翻译:通过将钢中的化学成分定义为规定范围,设定成为根据工作环境的成分参数公式的耐候性优异的钢材,由此减少流动锈,特别是即使在 提供海岸地区等咸况。 此外,还考虑到根据JIS G 0555的A型夹杂物和B型夹杂物的量,还提供了具有优异的抗震性和耐候性的钢材料,其也包括焊接热影响区域。
摘要:
A high tensile strength steel product for high heat input welding having excellent toughness in the heat-affected zone and having a tensile strength of at least 490 MPa contains, in terms of percent by weight, from about 0.05% to about 0.18% of C, 0.6% or less of Si, from about 0.80% to about 1.80% of Mn, 0.005% or less of Al, 0.030% or less of P, 0.004% or less of S, 0.005% or less of Nb, from about 0.04% to about 0.15% of V, from about 0.0050% to about 0.00150% of N, and from about 0.010% to about 0.050% of Ti, the ratio of the Ti content to the Al content, Ti/Al, satisfying 5.0 or more, and further contains at least one of from about 0.0010% to about 0.0100% of Ca and from about 0.0010% to about 0.0100% of REM, and the balance being Fe and incidental impurities. In the steel product, oxide inclusions containing, in terms of percent by weight, 20% to about 95% of a titanium oxide, 70% or less of Al2O3, 5% to about 50% in total of at least one of calcium oxide and a REM oxide, and 15% or less of MnO are dispersed.
摘要:
N—V(nitrogen-vanadium) containing continuous casting slab with no surface cracks suitable for the manufacture of non-tempered high tensile steel materials has a tensile strength of 490 MPa or more and excellent toughness. A method of manufacturing non-tempered high tensile steel materials uses the casting slab as the raw material. Compatibility between the desired properties of the materials utilizing VN and inhibition of the surface cracks of test pieces, can be attained by controlling the steel composition and the relationship between each of components of the steel thereby controlling precipitation of VN and MnS. A continuous casting slab with no surface cracks contains C, Si, Mn, P, S, Al, V, N, Ti, B, Ca and REM each within a specified range, and satisfies an equation for the relationship between V and N and a relationship between Mn and S.
摘要:
A high-strength heavy-wall H-shaped steel is excellent in Z-direction toughness at the flange thickness center. The heavy-wall H-shaped steel is comprised of by weight from about 0.05 to 0.18% C, up to about 0.60% Si, from about 1.00% to about 1.80% Mn, up to about 0.020% P, under 0.004% S, from 0.016% to 0.050% Al, from 0.04% to 0. 15% V, and from 0.0070% to 0.0200% N, and one or more of from about 0.02% to about 0.60% Cu, from about 0.02% to about 0.60% Ni, from about 0.02% to about 0.50% Cr, and from about 0.01% to about 0.20% Mo; and the balance being Fe and incidental impurities. Also, (V.times.N)/S.gtoreq.0.150; the Ti content is within a range satisfying 0.002.ltoreq.Ti.ltoreq.1.38.times.N-8.59.times.10.sup.-4 ; Ceq (=C+Si/24+Mn/6+Ni/40+Cr/5+Mo/4+V/14) is within a range of from about 0.36 wt % to about 0.45 wt %, and the yield strength is at least 325 MPa.
摘要:
A high-strength and high-toughness steel product having at least about 0.001% and less than about 0.030% by weight C, not more than about 0.60% by weight Si, from about 0.8% to 3.0% by weight Mn, from about 0.005 to 0.20% by weight Nb, from about 0.0003 to 0.0050% by weight B, and not more than about 0.005% by weight AL wherein at least 90% of the product has a bainite structure. A method of making this steel product is subject to less stringent production controls because of the nature of the composition.
摘要:
A method of manufacturing a thick steel product of high strength and high toughness having excellent weldability with minimal variation of material properties, comprises heating a steel raw material to the temperature of Ac.sub.3 to 1350.degree. C., hot rolling and then cooling at the cooling rate of 10.degree. C./sec. or less. The steel raw material has the following composition:C: 0.001-0.25 wt %;Mn: 1.0-3.0 wt %;Ti: 0.005-0.20 wt %;Nb: 0.005-0.20 wt %;B: 0.0003-0.0050 wt %; andAl: 0.01-0.100 wt %balance substantially Fe and incidental impurities. The composition has a transformation start temperature (Bs) of 670.degree. C. or less. Since the steel product obtained by the method has no variation in physical properties regardless of variation in cooling rate, it is possible to supply steel products of high strength and high toughness which have uniform microstructure and properties along their thickness direction and are excellent in weldability.
摘要:
A high-strength and high-toughness steel product having at least about 0.001% and less than about 0.030% by weight C, not more than about 0.60% by weight Si, from about 0.8 to 3.0% by weight Mn, from about 0.005 to 0.20% by weight Nb, from about 0.0003 to 0.0050% by weight B, and not more than about 0.005% by weight Al, wherein at least 90% of the product has a bainite structure. A method of making this steel product is subject to less stringent production controls because of the nature of the composition.
摘要:
The present invention relates to an H-shaped steel used as a building structure such as a column material or the like for highrise and super highrise building structures. In the bainite structure of extra-low-carbon steel, diffusive &agr;q is finely dispersed in &agr;B to ensure tensile strength at the 590-MPa level and significantly improve toughness in the direction of the flange thickness. Fine dispersion of &agr;q is achieved by controlling Mn and Cu in proper ranges. In other word, the present invention provides 590MPa class heavy gauge H-shaped steel with excellent as-rolled toughness in the direction of the flange thickness, containing 0.001 to 0.025 wt % of C, 0.6 wt % or less of Si, 0.4 to 1.6 wt % of Mn, 0.025 wt % or less of P, 0.010 wt % or less of S, 0.1 wt % or less of Al, 0.6 to 2.0 wt % of Cu, 0.25 to 2.0 wt % of Ni, 0.001 to 0.050 wt % of Ti, and 0.0002 to 0.0030 wt % of B, wherein Mn/Cu≦2.0 and 250≦117 Mn (wt %)+163 Cu (wt %)≦350 are satisfied.