Fuel storage and delivery systems are provided for storing pressurized liquefied natural gas (PLNG) fuel at a pressure of about 1035 kPa (150 psia) to about 7590 kPa (1100 psia) and at a temperature of about -123 °C (-190 °F) to about -62 °C (-80 °F) and delivering vaporized PLNG fuel on demand for combustion in an engine (24). The fuel storage and delivery systems have fuel storage containers (10) that are constructed from ultra-high strength, low alloy steel containing less than 9 wt.% nickel and having a tensile strength greater than 830 MPa (120 ksi) and a DBTT lower than about -73 °C (-100 °F). While not limited thereto, the present invention is especially useful for automobiles, buses, trucks and other vehicles with engines (24) designed to operate through combustion of natural gas.

LNG fuel storage and delivery systems for natural gas powered vehicles

An ultra-high strength boron-containing steel having a tensile strength of at least about 900 MPa (130 Ksi), a toughness as measured by Charpy V-notch impact test at -40 °F of at least 120 joules (90 ft-lbs), and a microstructure comprising predominantly fine-grained lower bainite, fine-grained lath martensite, or mixtures thereof, transformed from substantially unrecrystallized austenite grains and is prepared by heating a steel slab to a suitable temperature; reducing the slab to form plate in one or more hot rolling passes in a first temperature range in which austenite recrystallizes; further reducing said plate in one or more hot rolling passes in a second temperature range below said first temperature range and above the temperature at which austenite begins to transform to ferrite during cooling (10); quenching (12) said plate to a suitable Quench Stop Temperature (16); and stopping said quenching and allowing said plate to air cool (18) to ambient temperature.

Ultra-high strength, weldable, boron-containing steels with superior toughness

A seamless steel pipe for a line pipe having high strength and high toughness which has a chemical composition: c: 0.03 to 0.06 %, Si: 0.05 to 0.15 %, Mn: 1.6 to 2.0 %, Al: 0.010 to 0.10 %, Ni: 0.3 to 0.7 %, Mo: 0.10 to 0.40 %, V: 0.01 to 0.06 %, Nb: 0.003 to 0.03 %, Ti: 0.003 to 0.020 %, N: 0.0010 to 0.0100 %, and balance: Fe and inevitable impurities, with the proviso that Mo + 5V >/= 0.4 % and 2Nb - V </= 0 %. The seamless steel pipe is capable of securing the strength and toughness of the X80 grade with stability, and has heat-treatment characteristics which allows the achievement of desired strength with ease independently of the size of a pipe.

High strength, high toughness, seamless steel pipe for line pipe

Marine structures are provided that are constructed from ultra-high strength, low alloy steels containing less than 2.5 wt% nickel and having a tensile strength greater than 900 Mpa (130 ksi). A primary benefit is that the marine structures of this invention have a cost per unit strength substantially lower than that of currently available marine structures.

High strength marine structures

This invention provides a bainite steel material, such as a steel plate of a large thickness, a steel strip, a shape or a steel bar which have little scatter of quality in the direction of the thickness thereof and among different types of steel materials, wherein the bainite steel material comprises a composition containing not less than 0.001 wt.% and less than 0.030 wt.% of C, not more than 0.60 wt.% of Si, 1.00-3.00 wt.% of Mn, 0.005-0.20 wt.% of Nb, 0.0003-0.0050 wt.% of B, not more than 0.100 wt.% of Al and not less than 90 wt.% of bainite structure.

Bainite steel material of little scatter of quality and method of manufacturing the same

Disclosed herein is a niobium-containing weldable structural steel having good weldability which consists of 0.005-0.04% of C, 0.01-0.50% of Si, 1.20-2.50% of Mn, 0.01-0.07% of Nb, 0.005-0.030% of Ti, 0.005-0.06% of Al and the balance of iron and inevitable impurities whereby [C(%)+1ON(%)] is not greater than 0.10% and Ti(%)/[C(%)+1ON(%)] is from 0.05 to 0.60 in order to restrict the amount of martensite islands in the weld heat affected zone to not greater than 15% in terms of the area fraction.

Niobium-containing weldable structural steel having good weldability

The constructional steel has the compsn. (by wt.) 0.005-0.04% C, 0.01-0.50% Si, 1.20-2.50% Mn, 0.01-0.07% Nb, 0.005-0.030% Ti, 0.005-0.06% Al, balance Fe, the (C% + 10N%) content being is not >0.10% and the Ti%/(C% + 10N%) content being 0.05-0.60. The content of martensite islands in the heat affected zone is limited to is not >15% of an area section. The steel may also contain one or more of =0.50% Cu, =1.50% Ni, =0.50% Cr, =0.60% Mo, =0.10% V, =0.003% B, =0.02% Ce and =0.003% Ca. The steel is useful for oil and natural gas pipelines use in cold regions. It has a yield strength of 40-70 kp/mm2, good heat-affected zone toughness and improved weld cracking resistance even when using high heat input welding techniques.

Takasi Hosoya

Papers

Niobium-containing weldable structural steel having good weldability

Niobium-contg. constructional steel - with improved weldability, used for oil and gas pipelines