定价： 689元 / 折扣价： 586 元

定价： 975元 / 折扣价： 829 元 加购物车

定价： 1632元 / 折扣价： 1388 元 加购物车

定价： 345元 / 折扣价： 294 元 加购物车

定价： 819元 / 折扣价： 697 元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车

定价： 605元 / 折扣价： 515 元 加购物车

定价： 605元 / 折扣价： 515 元 加购物车

定价： 819元 / 折扣价： 697 元 加购物车

定价： 605元 / 折扣价： 515 元 加购物车

定价： 345元 / 折扣价： 294 元 加购物车

5.1 PCRT Applications and Capabilities—PCRT has been applied successfully to a wide range of NDT applications in the manufacture and maintenance of metallic and non-metallic parts. Examples of anomalies detected are discussed in 1.1. PCRT has been shown to provide cost effective and accurate NDT solutions in many industries including automotive, aerospace, and power generation. Examples of successful applications currently employed in commercial use include, but are not limited to:(1) Silicon nitride bearing elements(2) Steel, iron, and aluminum rocker and control arms(3) Aircraft and industrial gas turbine engine components (blades, vanes, disks)(4) Cast cylinder heads and cylinder blocks(5) Sintered powder metal gears and clutch plates(6) Machined forged steel steering and transmission components (gears, shafts, racks)(7) Ceramic oxygen sensors(8) Silicon wafers(9) Gears, including those with induction hardened or carburized teeth(10) Ceramic matrix composite (CMC) material samples and components(11) Components with shot peened surfaces(12) Machined or rolled-formed fasteners(13) Components made with additive manufacturing(14) Aircraft landing gear, wheel, and brake components(15) Components made with metal injection molding5.2 General Approach and Equipment Requirements for PCRT via Swept Sine Input: 5.2.1 PCRT systems comprise hardware and software capable of inducing vibrations, recording the component response to the induced vibrations, and executing analysis of the data collected. Inputting a swept sine wave into the part has proven to be an effective means of introducing mechanical vibration and can be achieved with a high quality signal generator coupled with an appropriate active transducer in physical contact with the part. Collection of the part’s frequency response can be achieved by recording the signal generated by an appropriate passive vibration transducer. The software required to analyze the available data may include a variety of suitable statistical analysis and pattern recognition tools. Measurement accuracy and repeatability are extremely important to the application of PCRT.5.2.2 Hardware Requirements—A swept sine wave signal generator and response measurement system operating over the desired frequency range of the test part are required with accuracy better than 0.002 %. The signal generator should be calibrated to applicable industry standards. Transducers must be operable over same frequency range. Three transducers are typically used; one Drive transducer and two Receive transducers. Transducers typically operate in a dry environment, providing direct contact coupling to the part under examination. However, non-contacting response methods can operate suitably when parts are wet or oil-coated. Other than fixturing and transducer contact, no other contact with the part is allowed as these mechanical forces dampen certain vibrations. For optimal examination, parts should be placed precisely on the transducers (generally, ±0.062 in. (1.6 mm) in each axis provides acceptable results). The examination nest and cabling shall isolate the Drive from Receive signals and ground returns, so as to not produce (mechanical or electrical) cross talk between channels. Excessive external vibration or audible noise, or both, will compromise the measurements.5.3 Constraints and Limitations: 5.3.1 PCRT cannot separate parts based on visually detectable anomalies that do not affect the structural integrity of the part. It may be necessary to provide additional visual inspection of parts to identify these indications.5.3.2 Excessive process variation of parts may limit the sensitivity of PCRT. For example, mass/dimensional variations exceeding 5 % may cause PCRT to be unusable.5.3.3 Specific anomaly identification is highly unlikely. PCRT is a whole body measurement and differentiating between a crack and a void in the same location is generally not possible. It may be possible to differentiate some anomalies by using multiple patterns and training sets. The use of physics-based modeling and simulation to predict the resonance frequency spectrum of a component may also allow relationships between resonance frequencies and defect locations/characteristics to be established.5.3.4 PCRT will only work with stiff objects that provide resonances whose frequency divided by their width at half of the maximum amplitude (Q) are greater than 400 to 500. Although steel parts may be very stiff and perfectly reasonable to use for PCRT, steel foil would generally not be.5.3.5 While PCRT can be applied to painted and coated parts in many cases, the presence of some surface coatings such as vibration-absorbing materials and heavy oil layers may limit or preclude the application of PCRT.5.3.6 While PCRT can be applied to parts over a wide range of temperatures, it should not be applied to parts that are rapidly changing temperature. The part temperature should be stabilized before collecting resonance data.5.3.7 Misclassified parts in the teaching set, along with the presence of unknown anomalies in the teaching set, can significantly reduce the accuracy and sensitivity of PCRT.1.1 This practice describes a general procedure for using the process compensated resonance testing (PCRT) via swept sine input method for metallic or non-metallic parts to compare resonance patterns from a sample under test to reference teaching sets of known acceptable and targeted defect samples. The resonance pattern differences can be used to distinguish acceptable parts with normal process variation from parts with targeted material states and defects that will cause performance deficiencies. These material states and defects include, but are not limited to, cracks, voids, porosity, shrink, inclusions, discontinuities, grain and crystalline structure differences, density-related anomalies, heat treatment variations, material elastic property differences, residual stress, and dimensional variations. This practice is intended for use with instruments capable of exciting, measuring, recording, and analyzing multiple whole body, mechanical vibration resonance frequencies in acoustic or ultrasonic frequency ranges, or both.1.2 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

The understanding and management of the interrelationship between human health, ecological condition, socio-cultural values, and economic well-being of the community and the high-value asset is essential to timely and acceptable restoration. This standard guide is designed to help responsible party(ies) with the identification and integration of affected stakeholders and with the establishment of a process to identify and resolve key issues essential to a satisfactory restoration. The standard guide is presented herein as a “framework” to help ensure that all the restoration planning process components (that is, human health, ecological condition, socio-cultural values and economic well-being) are considered. The framework is designed to allow a user to determine which components of the process are applicable to the restoration problem being addressed, and to establish the level of analytical detail necessary for each component. It provides general guidance to help with the selection of approaches and methods for specific analysis of each of the major restoration planning components (that is, human health, ecological condition, socio-cultural values, and economic well-being). By actively involving affected stakeholders in the restoration decision-making process, it will help the user to orient the process to prioritize and consider the most important issues of those who’s lives are most directly impacted by the consequences of the event and resulting restoration. This not only greatly increases the chances of a successful and acceptable restoration, but will also help promote public trust in the responsible party’s ability to rapidly restore the high-value asset(s).1.1 To ensure a publicly acceptable and timely restoration of an asset contaminated as a result of a natural or man-made disaster, including a terrorist event, it is essential to have a pre-planned strategy developed and tailored at the community level and facilitated by the government which advocates the support and involvement of the affected community during such a crisis period. This pre-planned strategy for restoration will need to be seamlessly incorporated into the overall emergency management process within the community. This guide presents a framework (that is, strategy) for involving the public in a stakeholder-focused, consensus-based event restoration process, for those situations where such involvement is essential to move a stalled (due to stakeholder issues) restoration process forward. This framework is designed to be an event-specific, community-specific process to help prioritize and consider actions necessary to optimize the restoration of an asset contaminated as the result of a disaster. 1.2 This guide is intended to describe a highly flexible restoration planning process, and therefore does not specify or recommend a specific course of action for this activity. 1.3 This guide is intended to assist in the implementation of a restoration planning process allowing a holistic assessment and balancing of the impacts associated with human health, ecology, socio-cultural values, and economic implications. It is intended to be used in alignment with current Federal Emergency Management Agency (FEMA) guidance and other guides and agency procedures and requirements to address specific stakeholder issues and concerns. 1.4 After completing the immediate response and stabilization phase of a disaster that required Federal assistance through establishment of a Joint Field Office (JFO) in accordance with the National Response Plan, mitigation and recovery activities will need to be planned and initiated to address the significant long-term impacts for any contaminated assets in the affected area. This guide provides a process that can be used by the JFO to gain stakeholder consensus on the restoration of these assets. 1.5 The user should consult other restoration-related standards, regulations, and sources for specific methods in the utilization of predictive models or other analysis tools that may be required under a restoration planning assessment. 1.6 Although the implementation of a restoration planning process is intended for use after a disaster occurs, it needs to be an integral part of a community’s pre-event planning activities and incorporated into appropriate community response plans. Identifying the important assets of a community and key stakeholders associated with each respective asset, before an event occurs through a process such as Community Asset Mapping, will help ensure a more efficient restoration process following an actual contamination of the asset in a disastrous event. 1.7 Since restoration planning as proposed in this guide follows a plan established prior to the event, it is important to coordinate asset restoration plans with event preplanning on how to minimize damages to significant assets from uncertain, low-probability, but potentially costly natural and man-made disasters. What will be required for asset restoration will be in part dependent on what measures have been taken to protect those same assets before the extreme event occurs. Guide E2506 provides a three-step protocol for formulating and evaluating risk mitigation strategies for constructed facilities. Assets identified for risk mitigation in the application of Guide E2506 prior to a disaster will likely be assets that the restoration stakeholders using this guide will want to consider restoring in the recovery phase following a disaster. 1.8 This standard guide does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard guide to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.

定价： 0元 / 折扣价： 0 元

This specification covers high-strength low-alloy steel shapes of structural quality, produced by quenching and self-tempering process (QST). The chemical analysis of the heat and of the steel product analysis shall conform to the chemical requirements prescribed by the reference materials. The Charpy V-notch test shall be performed to determine if the material conforms to the required tensile properties.1.1 This specification covers high-strength low-alloy structural steel shapes in Grades 50 [345], 60 [415], 65 [450], 70 [485], and 80 [550], produced by the quenching and self-tempering process (QST). The shapes are intended for riveted, bolted or welded construction of bridges, buildings and other structures.1.2 The QST process consists of in line heat treatment and cooling rate controls which result in mechanical properties in the finished condition that are equivalent to those attained using heat treating processes which entail reheating after rolling. A description of the QST process is given in Appendix X1.1.3 Due to the inherent characteristics of the QST process, Grade 50 [345], 60 [415], 65 [450], and 70 [485] shapes shall not be formed nor post weld heat treated at temperatures exceeding 1100°F [595°C] and Grade 80 [550] shapes shall not be formed nor post weld heat treated at temperatures exceeding 1000°F [540°C].1.4 When the steel is to be welded, it is presupposed that a welding procedure suitable for the grade of steel and intended use or service will be utilized. See Appendix X3 of Specification A6/A6M for information on weldability.1.5 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

This specification covers the requirements for chromium diffusion of metals applied by pack cementation process. The four classes of chromium diffusion coating, defined by the type of base metal, are as follows: Class I (carbon steels); Class II (low-alloy steels); Class III (stainless steels); and Class IV (nickel-based alloys). Specimens shall adhere to processing requirements such as substrate preparation, materials (masteralloys, activators, and inert fillers), loading, furnace cycle, post cleaning, post straightening, visual inspection, and marking and packaging. Specimens shall also adhere to coating requirements such as diffusion thickness, decarburization, chromium content, appearance, and mechanical properties (tensile strength, and macro- and micro-hardness).1.1 This specification covers the requirements for chromium diffusion of metals by the pack cementation method. Pack diffusion employs the chemical vapor deposition of a metal which is subsequently diffused into the surface of a substrate at high temperature. The material to be coated (substrate) is immersed or suspended in a powder containing chromium (source), a halide salt (activator), and an inert diluent such as alumina (filler). When the mixture is heated, the activator reacts to produce an atmosphere of chromium halides which transfers chromium to the substrate for subsequent diffusion. The chromium-rich surface enhances corrosion, thermal stability, and wear-resistant properties.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车