527 results about "Stress corrosion cracking" patented technology

A porous composite material useful in semiconductor device manufacturing, in which the diameter (or characteristic dimension) of the pores and the pore size distribution (PSD) is controlled in a nanoscale manner and which exhibits improved cohesive strength (or equivalently, improved fracture toughness or reduced brittleness), and increased resistance to water degradation of properties such as stress-corrosion cracking, Cu ingress, and other critical properties is provided. The porous composite material is fabricating utilizing at least one bifunctional organic porogen as a precursor compound

Methods of forming dielectric films comprising Si, C, O and H atoms (SiCOH) or Si, C, N and H atoms (SiCHN) that have improved cohesive strength (or equivalently, improved fracture toughness or reduced brittleness), and increased resistance to water degradation of properties such as stress-corrosion cracking, Cu ingress, and other critical properties are provided. Electronic structures including the above materials are also included herein.

The method for detecting stress corrosion cracking (SCC) of pipelines, comprising the steps of: identifying pipeline locations and pipeline conditions that are amenable to inspection by a magnetic flux inline tool and by a TFI tool; performing two inspections on the pipeline, one inspection performed using the magnetic flux inline (MFL) tool and an other inspection performed using the TFI tool; aligning signal features resulting from the two inspections; identifying TFI signals occurring above a specified threshold; identifying MFL signals for a section of pipeline corresponding to the identified TFI signals; for the identified TFI signals, determining whether the MFL signals are below a second threshold level; designating the sections of the pipeline corresponding to identified TFI signals above the threshold and below the second threshold as a potential corrosion feature; identifying TFI signals that exceed a defined metal loss percentage; measuring a width and length of the signal features, and if the width and length of the signal feature exceed threshold crack width and length values, designating as a potential corrosion feature section of pipeline corresponding to the identified TFI signals.

A phased array ultrasonic testing system is for examining turbine disc bores and blade attachments for discontinuities, such as stress corrosion cracking. The system is particularly suited to perform an accurate and efficient inspection of components despite their having a relatively complex geometry, such as axial entry blade attachments and bores of associated discs. The system includes a control system with a computer and a controller for programming, emitting, and steering an ultrasonic beam via at least one two-dimensional phased array probe, thereby precisely inspecting the area of interest while simultaneously accommodating the aforementioned complex geometry of the disc or blade attachment. Computer control of the beam permits the number of inspection locations and the number of different probe wedges to be reduced providing for an efficient, timely inspection. Methods of profiling and examining turbine components of known and unknown geometries, are also disclosed.

A method and system for reducing stress corrosion cracking in a hot water system, such as a nuclear reactor, by reducing the electrochemical corrosion potential of components exposed to high temperature water within the structure. The method comprises the steps of: providing a reducing species to the high temperature water; and providing a plurality of noble metal nanoparticles having a mean particle size of up to about 100 nm to the high temperature water during operation of the hot water system. The catalytic nanoparticles, which may comprise at least one noble metal, form a colloidal suspension in the high temperature water and provide a catalytic surface on which a reducing species reacts with least one oxidizing species present in the high temperature water. The concentration of the oxidizing species is reduced by reaction with the reducing species on the catalytic surface, thereby reducing the electrochemical corrosion potential of the component.

A method and apparatus for improving the fatigue and stress corrosion cracking performance of irregular surfaces, such as welds assemblies of components, using a positioning system, such as a robotic or CNC machine, to position a tool head for inducing compression along and into the surface of a workpiece to automatically follow the surface irregularities. The method and apparatus operates to follow a virtual control surface located below the actual surface of the workpiece thereby allowing the irregular topography surface to be uniformly processed with closed loop process control.

A method and system for designing a part with improved fatigue life and resistance to stress corrosion cracking in which residual stresses existing in the part are accounted for. The performance criteria and operating conditions of the part are assessed and a total stress state is determined from the sum of the residual stresses and applied stresses acting on the part. Unified Fatigue Performance Model or Smith-Topper-Neuber parameters are used to determine fatigue life functions which, in turn, are used in conjunction with a fatigue design diagram to determine the appropriate residual stress to introduce in order to optimize the part's resistance to stress induced failure mechanisms. A residual stress distribution is then designed to avoid distortion of the part while still imparting the beneficial effects of compressive residual stress.

The invention relates to high-strength low-temperature steel with high hydrogen induced cracking (HIC) and sulfide stress corrosion cracking (SSC) resistance and a manufacturing method thereof. A low alloy steel component system with ultra-low C content, low Si content, medium Mn content, low Als content, low N content, a little alloyed Ni and Mo and trace Ti and Nb is adopted, Mn/C is more than or equal to 22, the segregation index 1.32 (percent C)*[(1.53 (percent Mn)+1.37 (percent Si)+1.15 (percent Mo)+1.06 (percent Cr)+(percent Cu)+0.86 (percent Ni)]*[(30 (percent P)+10 (percent S)] is less than or equal to 0.060, [(percent Si)+(percent Als)]*(percent C) is less than or equal to 0.0035, Pcm is less than or equal to 0.018 percent, Nib/Ti is 1.5 to 3.5, Ca treatment is performed, Ca/S is 0.80 to 3.00, the microstructure of a finished steel plate product consists of uniform and fine acicular ferrites and a few upper bainites by optimizing a thermal mechanical control processing (TMCP) technology, and the average particle size is less than 10mu m; and the characteristics of high strength, toughness and HIC and SSC resistance are achieved, high heat input welding can be performed, and the steel is particularly suitable for manufacturing a low temperature storage tank, a low temperature pressure steel pipe, an ocean platform in an ice sea area, and the like.

The invention discloses pipeline steel excellent in acid corrosion resistance on the seabed. The pipeline steel comprises, by weight, 0.020-0.050% of C, 0.10-0.30% of Si, 0.50-1.10% of Mn, 0.012% of P or less, 0.0015% of S or less, 0-0.20% of Cu, 0-0.30% of Cr, 0-0.20% of Ni, 0-0.25% of Mo, 0.030-0.055% of Nb, 0.020-0.050% of V, 0.010-0.025% of Ti, 0.010-0.050% of Al and 0.008% of N or less. A production method comprises the steps of heating after continuous casting and blank forming, rough rolling, precise rolling, cooling, reeling and cooling to indoor temperature. By means of the pipeline steel and the production method, an ideal complex-phase structure containing ultra-fine grain polygonal ferrite and a small number of methyl acrylate (MA) components which are distributed dispersively can be obtained, the Rt0.5 is equal to or higher than 485 MPa, the Rm is equal to or higher than 570 MPa, -20 DEG C KV2 is equal to or higher than 250 J, and -15 DEG C DWTT SA is equal to or higher than 85%. A hydrogen induced crack j (HICj) test and a sulfide stress corrosion cracking (SSCC) test indicate that no fracture or crack occurs.

The invention discloses a converter smelting and external refining control method of HIC (Hydrogen Induced Crack)/SSCC (Sulfide Stress Corrosion Cracking)-preventing steel. A smelting process route of converter-CAS (Control Automatic System) station-LF (Low Frequency) refining-VD (Vacuum Distillation)/RH (Relative Humidity) vacuum-calcium treatment-soft blowing-continuous casting is adopted. Low-phosphor requirements of the HIC/SSCC-preventing steel are obtained through controlling the converter smelting process route; and meanwhile, part of deoxidation type inclusions are removed by carrying out strong deoxidation, alloying as well as residue washing in a converter steel-tapping process, and over 60% of sulfur in molten steel is removed by sufficient stirring of the residue washing. In the LF refining process, refining furnace slag which is high in alkalinity, high in Al2O3 and strong in reducibility is obtained by regulating components of the refining furnace slag, and the inclusions are transformed and removed towards a low melting point by virtue of balance of the furnace slag-molten steel-inclusions. Proper vacuum treatment time and vacuum degree are kept at a vacuum treatment furnace so as to remove part of gas and inclusions, excessive calcium line is fed into the molten steel after being broken in air, and then the molten steel is softly blown and stirred for over 20 minutes to obtain the molten steel with ultralow oxygen and ultralow sulfur.

This invention relates to permanent, ultrasonic, flexible, dry-coupled, linear arrays for the inspection of pipelines, process equipment, and the like. The permanent, ultrasonic, flexible, dry-coupled, linear arrays detect and/or measure corrosion wall loss, stress corrosion cracking, and/or internal initiated pipeline cracking. The apparatus for ultrasonically testing materials includes a linear array of ultrasonic sensors, and a flexible, acoustically transmissive, dry-coupling surrounding at least a portion of each of the ultrasonic sensors.

An aluminum alloy extruded material in relation with the present invention is with high strength by die quench air cooling and excellent in SCC resistance. The aluminum alloy extruded material is an Al—Zn—Mg-based aluminum alloy extruded material for structural member for automobiles such as a bumper reinforce, a door guard bar and the like which satisfies three expressions of 5.0≦[Zn]7.0, [Zn]/5.38<[Mg]≦[Zn]/5.38+0.7, and [Zn]+4.7[Mg]≦14, where [Mg] represents mass % of Mg and [Zn] represents mass % of Zn, and contains at least either one element of Cu: 0.1-0.6 mass % and Ag: 0.01-0.15 mass %, Ti: 0.005-0.05 mass %, and at least one element out of Mn: 0.1-0.3 mass %, Cr: 0.05-0.2 mass %, Zr: 0.05-0.2 mass %.

A method for predicting the location of stress corrosion cracking in a steel gas pipeline in which in-line stress corrosion cracking smart tool data, external low level metal loss data and soil characterization data are compiled to predict the location of stress corrosion cracking in a steel gas pipeline segment.

Polyamides made from 1,6-hexanediamine, and the dicarboxylic acids 1,10-decandioic acid and/or 1,12-dodecanedioic acid, and terephthalic acid in specified proportions are particularly resistant to salt stressed (induced) corrosion cracking. This makes them particularly useful as vehicular parts which may be exposed to salts. Particularly when these polyamides contain tougheners and/or plasticizers they are especially useful for hoses and tubes.

Low-alloy steels and methods of manufacturing pipes having a wall thickness greater than or equal to about 8 mm and less than or equal to about 35 mm therefrom are provided. In one embodiment, a steel composition is processed that yields an average prior austenite grain size greater than about 15 or 20 μm and smaller than about 100 μm. A quenching sequence has been determined that yields a microstructure of greater than or equal to about 60% martensite by volume, and less than or equal to about 40% by volume lower bainite, without substantial formation of ferrite, upper bainite, or granular bainite. The yield strength of the quenched and tempered pipes may be greater than about 70 ksi, 80 ksi, or 90 ksi. The quenched and tempered pipes are suitable for 70 ksi, 80 ksi, and 90 ksi grades and resistant to sulfide stress corrosion cracking.

The object of this invention is to provide a method for mitigating a stress corrosion cracking of reactor structural material which makes it possible to suppress the rise in the main steam line dose rate without secondary effects such as a rise in the concentration of radioactive cobalt-60, etc. in the reactor water. Hydrogen and a reductive nitrogen compound containing nitrogen having a negative oxidation number (for example, hydrazine) are injected into the core water of boiling water nuclear power plant. By injecting the reductive nitrogen compound containing nitrogen having a negative oxidation number into the core water, the stress corrosion cracking of structural material of reactor can be mitigated without side reactions such as a rise in the concentration of cobalt-60, etc.

The invention relates to the field of manufacturing of a steel plate for a pressure container, and particularly relates to a steel plate for a 500MPa-level pressure container for resisting sulfide stress corrosion cracking and a production method thereof. The steel plate is prepared from the following components by mass percent: no more than 0.20% of C, 0.15-0.50% of Si, no more than 1.35% of Mn, no more than 0.012% of P, no more than 0.002% of S, no more than 0.10% of Nb, V and Ti, 0.020-0.050% of Alt, and the balance of Fe and inevitable impurities. The steel plate has the beneficial effects that each component is accurately controlled in the smelting process, the content of harmful elements such as P, S and the like in steel is strictly controlled, the cleanliness of molten steel is improved, a continuous casting blank is heated after being slowly cooled by a burial pit or a slow cooling cover, and the steel plate for the pressure container having the advantages of resisting sulfide stress corrosion cracking, hydrogen-induced cracking and lamellar tearing, high temperature resistance, being easy to weld, and the like is obtained by reasonably controlling slowly cooling and normalizing heat treatment processes of rolled and steel plates.

New and used parts of gas and steam turbine engines are protected by imparting a controlled residual compressive stress to given portions of the part and then coated by a CVD or PVD process at low temperatures with layers of TiN or alloys thereof at alternate selective hard and less hardened levels. The protective treatment is particularly efficacious for airfoils of compressor blades/vanes of gas turbine engines and airfoils of airfoils and certain components of steam turbine engines. This method is targeted to reduce erosion, corrosion and stress-corrosion cracking in these parts.