A low carbon alloy steel tube and a method of manufacturing the same, especially for a stored gas inflator pressure vessel, in which the steel tube consists essentially of, by weight: about 0.06% to about 0.18% carbon, about 0.3% to about 1.5% manganese, about 0.05% to about 0.5% silicon, up to about 0.015% sulfur, up to about 0.025% phosphorous, and at least one of the following elements: up to about 0.30% vanadium, up to about 0.10% aluminum, up to about 0.06% niobium, up to about 1% chromium, up to about 0.70 % nickel, up to about 0.70 % molybdenum, up to about 0.35 % copper, up to about 0.15% residual elements, and the balance iron and incidental impurities. After a high heating rate of about 100 °C. per second; rapidly and fully quenching the steel tubing in a water-based quenching solution at a cooling rate of about 100 °C. per second. The steel has a tensile strength of at least about 145 ksi and as high as 220 ksi and exhibits ductile behavior at temperatures as low as -100 °C.

Low carbon alloy steel tube having ultra high strength and excellent toughness at low temperature and method of manufacturing the same

The invention discloses a welding method for Q345qDNH weather-resisting steel for a bridge According to the welding method provided by the invention, specific to the special chemical components, suitable technical conditions and different slab thickness of the Q345qDNH weather-resisting steel for the bridge, a welded joint is jointed in a butt-jointed or T-shaped corner jointed form According to the welding method, submerged-arc welding, drug core CO2 gas shielding semi-automatic welding or shielded metal arc welding is adopted and the weld preheating temperature is confirmed according to the different slab thickness According to the welding method provided by the invention, the joint form and the thickness size of a bridge structure are completely covered; the technical scheme is simple and the applicability is strong; the implementing effect meets the technical demands of the present related standard for the construction of the bridge steel and the bridge structure; and the welding method can be practically applied to the welding of the Q345qDNH weather-resisting steel bridge structure

Welding method for Q345qDNH weather-resisting steel for bridge

An atmosphere corrosion resisting steel plate having high strength and excellent bending formability, characterized in that it has a chemical composition, in mass %: C: 0.05 to 0.15 %, Si: 0.5 % or less, Mn: 0.5 to 2.0 %, P: 0.02 % or less, S: 0.005 % or less, Ni: 0.2 to 2.0 %, Cu: 0.2 to 0.5 %, Cr: 0.2 to 1.0 %; one or more of Ti: 0.03 to 0.2 %, Nb: 0.01 to 0.07 %, V: 0.01 to 0.07 % and B: 0.0005 to 0.0050 %, and balance; Fe and inevitable impurities. A method for producing the above steel plate which comprises heating a steel material having the above composition at a temperature of 1200ringC or higher, completing rolling at a temperature in the range of 850 to 950ringC, and taking up the rolled product at a temperature in the range of 500 to 650ringC. The steel plate secures a ultra high strength of a yield strength of 700 MPa or more, and can endure a bending operation after blasting or the like, and further has good atmosphere corrosion resistance.

Atmosphere corrosion resisting steel plate having high strength and excellent bending formability and method for production thereof

The invention relates to a method for using Ti micro alloy technique to product 700MPa high-strength steel, based on sheet casting process, wherein it can avoid vibrated steel properties. And it has simple control and high efficiency. The yield strength of said steel is 700-780MPa, while the thickness is 1.5-8.0mm.

Method for manufacturing 700MPa high-strength weathering steel based on thin slab continuous casting and rolling flow by use of Ti microalloying process

A low carbon high strength steel consists essentially of, by weight, about 0.07% to about 0.12% carbon, about 0.70% to about 1.60% manganese, up to about 0.020% phosphorous, up to about 0.015% sulfur, about 0.06% to about 0.35% silicon, about 0.25% to about 1.20% chromium, up to about 0.65% nickel, about 0.20% to about 0.70% molybdenum, up to about 0.35% copper, about 0.02% to about 0.06% aluminum, up to about 0.05% vanadium, up to about 0.25% residual elements, and the balance iron.

Low-carbon high-strength steel

A method of making a weathering grade steel plate includes the steps of establishing a minimum yield strength plate thickness target from one of 344MPa (50KSI) up to 10.16cms (4'), 447MPa (65KSI) up to 3.81cms (1.5'), and 481MPa (70KSI) up to 3.17cms (1.25'). A modified weathering grade alloy composition is cast into a slab employing effective levels of manganese, carbon, niobium, vanadium, nitrogen, and titanium. The cast slab is heated and rough rolled to an intermediate gauge plate. The intermediate gauge plate is controlled rolled and subjected to one of air cooling or accelerated cooling depending on the minimum yield strength and thickness target. With the controlled alloy chemistry, rolling and cooling, the final gauge plate exhibits discontinuous yielding and can be used for applications requiring a 481MPa (70KSI) minimum yield strength in plate thicknesses up to 3.17cms (1.25'), a 447MPa (65KSI) minimum yield strength in plate thickness up to 3.81cms (1.50') and a 344MPa (50KSI) minimum yield strength for plates as thick as 10.16cms (4').

Choo Wung-Yong

Papers

Method of making an as-rolled multi-purpose weathering steel plate and product therefrom