Abstract: An enameling steel having excellent strength after fire includes up to 0.008% C, 0.25-0.35% Mn, 0.03-0.05 Al, 0.010 to 0.014 N and 0.020-0.025 Nb.

Abstract: The invention refers to a process for production of raw stainless steel castings, in particular for stainless steel strip, covering rolling and annealing of cast material if required, as well as de-scaling, in particular by pickling in aqueous media, and coiling for raw stainless steel strip if necessary. In order to achieve greater flexibility as regards steel grades that can be treated and dimensions of the castings, the material is to be heat-treated in batches and preferably also annealed, cooled and de-scaled immediately after the final heat treatment stage, without intermediate storage, in batches. In a process covering the process stages for casting, rolling of the cast material if necessary, cooling, as well as de-scaling, in particular by pickling in aqueous media, and coiling, if necessary, to form raw stainless steel coils, the material is to be cast in batches and de-scaled immediately afterwards without intermediate storage in order to obtain the same advantage.

Abstract: A bumper beam for vehicles is formed from cold-rolled sheet steel having an initial tensile strength of approximately 70 ksi. The steel sheet is roll formed in a desired cross-section and swept into a curvature corresponding to the vehicle requirements before the steel sheet is heat treated by induction heat and quenched to provide a bumper beam having a tensile strength from 100 ksi up to approximately 260 ksi.

Abstract: A billet of steel has a composition comprising small amounts of hardenability agents. The billet is hot rolled into a continuous bar, in two hot rolling stages with an intervening cooling step employing a turbulent cooling liquid. After the second hot rolling stage, the bar is gathered into a succession of closely overlaying loops and moved along a roller conveyor where the overlapping loops are cooled by air blowers, after which the bar is coiled. The resulting hot rolled bar has a microstincture consisting essentially of bainite in fine-sized packets reflecting an average austenitic grain size, before the gathering and cooling steps, of 8-11 ASTM. A threaded fastener in its final form can be produced from the hot rolled bar by a cold deforming operation without a heat treating operation before or after cold deforming. The threaded fastener is undistorted and contains residual compressive stresses.

Abstract: The present invention provides hot rolled steel plates and sheets having a tensile strength of 34 to 62 kgf/mm.sup.2 and excellent in a uniform elongation even after cold working the steel plates and sheets to give round and square tubes, shapes, sheet piles, etc., to such an ordinary degree that the productivity is not lowered, and a process for producing the hot rolled steel plates and sheets. The hot rolled steel plates and sheets contain from 0.04 to 0.25% of C, from 0.0050 to 0.0150% of N and from 0.003 to 0.050% of Ti, also contain from 0.0008 to 0.015% of TiN having a particle size exceeding 1 .mu.m and dispersed in the matrix thereof, and have Ceq. (WES) of 0.10 to 0.45%. The process comprises heating a steel slab containing the constituents as mentioned above to 1,000 to 1,300.degree. C., starting to roll the steel slab subsequently and finishing rolling at a temperature of at least the Ar.sub.3 transformation point, and air cooling from a temperature of at least 500.degree. C.

Abstract: A high yield ratio-type, hot rolled high strength steel sheet excellent in both formability and spot weldability, containing not less than 5% of retained austenite, and a process for producing the same are provided. The steel sheet contains 0.05 to less than 0.15% by weight or 0.15 to less than 0.30% by weight of C, 0.5 to 3.0% by weight of Si, 0.5 to 3.0% by weight of Mn, more than 1.5 to 6.0% by weight of Si and Mn in total, not more than 0.02% by weight of P, no more than 0.01% by weight of S, and 0.005 to 0.10% by weight of Al, the balance essentially being Fe, and is composed of three phases of ferrite, bainite and retained austenite as a microstructure, and having a ratio (V.sub.F /d.sub.F) of ferrite volume fraction (V.sub.F) to ferrite grain size (d.sub.F) of not less than 20 (not less than 7 in case of 0.15 to less than 0.30% by weight of C), a volume fraction of retained austenite having grain sizes of not more than 2 .mu.

Abstract: To produce a thin strip having a high cast strip toughness from a thin cast strip of a Cr-stainless steel containing Nb, Ti, and Al in an amount of 0.05% or more, a process includes the steps of: casting a thin cast strip of a Cr-stainless steel having a thickness of 10 mm or less, the steel containing 13-25 wt % of Cr, 0.05-1 wt % of one or more of Nb, Ti, Al and V in terms of a total amount, 0.03 wt % or less of C, 0.03 wt % or less of N, and 0.3-3.0 wt % of Mo in accordance with need, and having a .gamma.p value of 0% or less; hot-rolling the thin cast strip in a temperature range of from 1150.degree. to 950.degree. C. at a reduction in thickness of 5 to 50% to form a thin strip; either slowly cooling the thin strip at a rate of 20.degree. C./sec or less or holding the thin strip for 5 sec or more, in a temperature range of from 1150.degree. to 950.degree. C.; and then coiling the thin strip at a temperature lower than 700.degree. C..gamma.p(%)=420C+470N+23Ni+9Cu+7Mn-11.5Cr-11.

Abstract: A method of manufacturing a cold rolled steel sheet includes the steps of preparing, as a material, a steel whose composition consists of C: 0.004 wt % or less, Si: 0.10 wt % or less, Mn: 0.50 wt % or less, Ti: between 0.01 wt % and 0.10 wt %, Nb: between 0.003 wt % and 0.03 wt %, B: between 0.001 wt % and 0.004 wt %, Al: between 0.03 wt % and 0.10 wt %, P: 0.025 wt % or less, S: 0.01 wt % or less, N: 0.006 wt % or less; performing a hot rolling on the material steel under the conditions of a finishing temperature between 800.degree. C. and 900.degree. C.; coiling the material at a temperature lower than 650.degree. C.; performing a cold rolling; performing a continuous annealing at a temperature between 830.degree. C. and Ac.sub.3 transformation point; and performing a skin pass rolling.

Abstract: A heat-resistant ferritic stainless steel plate or foil having improved toughness as well as workability is disclosed, which consists essentially of:C: not larger than 0.020%,N: not larger than 0.020%,wherein,C(%)+N(%): not larger than 0.030%,Si: not larger than 1.0%,Mn: not larger than 1.0%,orone or more of Si: larger than 1.0% but not larger than 5.0% and Mn: larger than 1.0% but not larger than 2.0%,Cr: 9.0-35.0%,Al: 3.0-8.0%,Y: 0.010-0.10%,Ti: 0.010-0.10%,Mo: 0-5.0%,Fe and incidental impurities: balance,and which is manufactured by cooling the hot-rolled steel plate at a cooling rate of 20.degree. C./sec- or higher immediately after hot rolling, coiling the hot-rolled steel plate at a temperature of 400.degree. C. or lower, and preferably cold rolling the resulting hot-rolled steel plate until the thickness thereof reaches 50 micrometers or less, and applying Al vapor deposition to both sides of the thus-obtained foil to a thickness of 0.2-4.0 micrometers.

Abstract: A low-yield-ratio high-strength hot-rolled steel sheet having the advantageous features of both conventional precipitation-strengthened steel and structure-strengthened steel and free from the drawbacks of these conventional steels, and a manufacturing method characterized in hot-rolling such a steel sheet. The steel sheet has an upper limit of C content of about 0.18 wt. %, and the lower C content limit approximately satisfies C.gtoreq.0.05+Ti/4+Nb/8 in relationship with the content of Ti and/or Nb. The steel sheet also contains about 0.5 to 2.5 wt. % Si and has a structure essentially formed of ferrite in which a carbide of Ti and/or Nb is precipitated, martensite and retained austenite.

Abstract: The present invention relates to a high-strength coil spring useful for an engine and other high-strength springs requiring a high fatigue-resistance and a method of producing the same.In general, a higher tensile strength is desired for spring materials but it has been known that if a tensile strength exceeds a certain limit, a toughness and a fatigue resistance are contrarily reduced.In addition, a coil spring has been used after forming and then being subjected to a quenching treatment followed by being subjected to a shot peening treatment to add a compressive residual stress to a surface thereof but an effective shot peening treatment gives a surface roughness Rmax of 6 to 20 .mu.m, so that not only it has been impossible to remove surface defects having a surface roughness of 6 to 20 .mu.m or less but also impressions due to the shot peening have covered the surface defects to be turned into injured portions and fatigue nuclei in many cases.

Abstract: A bake hardening cold-rolled steel sheet which has good bake hardenability, good dent resistance, and low yield ratio which contributes to the shape-fixability of the steel sheet. The steel is suitable for the outer panel of an automobile. The process for manufacturing the steel sheets includes the following steps:(1) preparing a melting steel which contains 0.02 to 0.06% carbon by weight, 0.60% to 1.40% manganese by weight, 0.5% silicon by weight at most, 0.1% phosphorus by weight at most, 0.1% aluminum by weight at most, 0.01% nitrogen by weight at most, 0.1% titanium by weight at most, and 50 ppm of boron at most;(2) preparing steel ingots by continuous casting the melting steel;(3) hot rolling the steel ingots to hot-rolled bands;(4) coiling the hot-rolled bands at temperature ranging from 560.degree. C. to 720.degree. C.;(5) after cold rolling, soaking the steel sheets at temperature ranging from 780.degree. C. to 900.degree. C.