摘要:
The invention relates to a hot-rolled ferritic steel sheet, the composition of the steel of which comprises, the contents being expressed by weight: 0.001≦C≦0.15%, Mn≦1%, Si≦1.5%, 6%≦Al≦10%, 0.020%≦Ti≦0.5%, S≦0.050%, P≦0.1%, and, optionally, one or more elements chosen from: Cr≦1%, Mo≦1%, Ni≦1%, Nb≦0.1%, V≦0.2%, B≦0.010%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the average ferrite grain size dIV measured on a surface perpendicular to the transverse direction with respect to the rolling being less than 100 microns.
摘要:
The present invention provides high strength thin-gauge steel sheet with excellent elongation and hole expandability having a tensile strength of 500 MPa or more and a method of production of high strength thin-gauge steel sheet with excellent elongation and hole expandability enabling production of this on an industrial scale, that is, high strength thin-gauge steel sheet comprised of, by mass %, C: 0.03 to 0.25%, Si: 0.013 to 0.299%, Mn: 0.8 to 3.1%, P≦0.02%, S≦0.02%, Al≦2.0%, N≦0.01%, and a balance of Fe and unavoidable impurities and having a microstructure comprised of ferrite with an area fraction of 10 to 85% and residual austenite with a volume fraction of 1 to 10%, an area fraction of 10% to 60% of tempered martensite, and a balance of bainite.
摘要:
The method for manufacturing cold-rolled steel sheet comprises the steps of: rough-rolling a slab using a rough-rolling unit; finish-rolling the sheet bar using a continuous hot finishing-rolling mill; cooling the hot-rolled steel strip on a runout table; coiling thus cooled hot-rolled steel strip; and applying picking, cold-rolling the hot-rolled steel strip, and final annealing to the cold-rolled steel strip.
摘要:
Method for producing a galvannealed steel sheet wherein a slab consisting essentially of C in an amount of 0.004 wt. % or less, N in an amount of 0.004 wt. % or less, Ti in an amount of 0.01 to 0.15 wt %, Si in an amount of 0.05 wt. % or less, Mn in an amount up to 2.5 wt. %, P in an amount up to 0.1 wt. %, S in an amount of 0.015 wt. % or less, sol. Al in an amount of 0.02 to 0.1 wt. % and the balance being Fe, is soaked for at least 30 minutes at a specified temperature (range). The soaked slab is hot rolled to produce a hot-rolled steel sheet which is coiled at a temperature of 500 to 700.degree. C. The coiled hot-rolled steel sheet is cold rolled at a reduction ratio of 60% or more to produce a cold-rolled steel sheet which is annealed at a temperature of from recrystallization temperature to Ac3 transformation temperature. Galvanizing the annealed cold-rolled steel sheet and then galvannealing at a temperature of 450 to 600.degree. C.
摘要:
Provided are: a galvannealed steel sheet, improved in the adhesiveness of a plated layer with a base steel sheet, as a galvannealed steel sheet, prepared by using a high-strength steel sheet as a base material; and a method for producing the galvannealed steel sheet. A galvannealed layer is formed on the base steel sheet including a high-strength steel having a predetermined composition. The average amount of Fe in the galvannealed layer is 8.0 to 12.0%. The absolute value of a difference (ΔFe) between the amount of Fe in the vicinity of an interface with the base steel sheet and the amount of Fe in the vicinity of the external surface of the plated layer in the plated layer is 0.0 to 3.0%.
摘要:
The invention relates principally to a hot rolled steel sheet with a yield stress greater than 690 MPa and less than or equal to 840 MPa, with strength between 780 MPa and 950 MPa, elongation at failure greater than 10% and a hole expansion ratio (Ac) greater than or equal to 50%.The chemical composition of the sheet claimed by the invention contains, whereby the contents are expressed in percent by weight: 0.40%≦C≦0.065%, 1.4%≦Mn≦1.9%, 0.1%≦Si≦0.55%, 0.095%≦Ti≦0.145%, 0.025%≦Nb≦0.045%, 0.005%≦Al≦0.1%, 0.002%≦N≦0.007%, S≦0.004%, P
摘要:
The present invention provides a ferritic stainless steel casting and a sheet thereof excellent in deep drawability, punch stretchability and ridging resistance and a method for producing the casting and the sheet. In the present invention, a chemical composition is controlled so that the amounts of C, N, Si, Mn, P and Ti may be reduced to the utmost for securing high workability and, on the basis of the chemical composition, the roping and ridging of a steel sheet product is reduced by adding Mg, thus dispersing Mg containing oxides that accelerate the formation of nuclei for solidification and, resultantly, suppressing the development of coarse columnar crystals in a casting. The present invention is characterized in that the average composition of the Mg containing oxides dispersing in a casting satisfies the following expressions and , 17.4(Al2O3)+3.9(MgO)+0.3(MgAl2O4)+18.7(CaO)≦500 , (Al2O3)+(MgO)+(MgAl2O4)+(CaO)≧95 .
摘要翻译:本发明提供一种铁素体不锈钢铸件及其深冲性,冲压伸缩性和抗皱性优异的片材以及铸造和片材的制造方法。 在本发明中,化学成分被控制为使得可以将C,N,Si,Mn,P和Ti的量最大限度地降低以确保高的可加工性,并且基于化学成分,卷绕和起皱 通过添加Mg来还原钢板产品,从而分散加速形成核固化的含Mg氧化物,从而抑制铸造中的粗大柱状晶体的发展。 本发明的特征在于,分散在铸件中的含Mg氧化物的平均组成满足以下表达式2和3,17.4(Al 2 O 3)+3.9(MgO)+0.3(MgAl 2 O 4)+18.7(CaO) (Al 2 O 3)+(MgO)+(MgAl 2 O 4)+(CaO)> = 95 3。
摘要:
A hot rolled steel having improved formability and minimal silver formation is made with a method comprising the addition of titanium and boron to the molten steel to combine with and remove the free nitrogen prior to rolling. Titanium is added so that the amount of nitrogen remaining after Ti addition is less than or equal to about 0.0035 wt % and boron is added to remove the balance of the nitrogen by forming BN.
摘要:
A cold rolled steel sheet including about 0.001 weight percent or less of carbon (C), about 0.1 weight percent or less of silicon (Si), about 0.3 weight percent or less of manganese (Mn), about 0.05 weight percent or less of phosphorus (P), about 0.003 weight percent or less of sulfur (S), about 0.1 weight percent or less of aluminum (Al), about 0.002 weight percent or less of nitrogen (N), about 0.005 to 0.02 weight percent of titanium (Ti), about 0.001 to 0.01 weight percent of niobium (Nb), and the balance iron and incidental impurities. The total weight percent of carbon, sulfur, and nitrogen is about 0.004 weight percent or less. The content of titanium, carbon, sulfur and nitrogen satisfies the equation: about 4.times.(C wt %).ltoreq.(Ti wt %)-48/14(N wt %)-48/32(S wt %).ltoreq.about 12.times.(C wt %). The method of the invention includes uniformly heating a steel slab having a composition as described above at a temperature T(K) satisfying the following equation: T(K).times.(C wt %+S wt %).ltoreq.about 4.0, and within a temperature range from abut 900.degree. to 1,300.degree. C., hot rolling at a finishing temperature of higher than the A.sub.C3 transformation temperature, coiling at a temperature of about 650.degree. C. or less, cold rolling after pickling at a rolling reduction rate of about 65 to 90 percent, and recrystallization-annealing at a temperature ranging from about 700.degree. to 950.degree. C.