4.1 The comparison of observed graphite particles with the structures shown in the charts give only purely descriptive information on the type, distribution, and size of the graphite in the sample being evaluated. It does not indicate, except in a very broad way, the origin of the graphite or the suitability of the iron-carbon alloy for a particular service.1.1 This test method covers the classification of graphite in cast irons in terms of type, distribution, and size by visual comparison to reference photomicrographs. This test method is intended to be applicable for all iron-carbon alloys containing graphite particles, and may be applied to gray irons, malleable irons, compacted graphite irons, and the ductile (nodular) irons.1.2 The reference photomicrographs included in this test method are in no way to be construed as specifications. In an appropriate specification for a specific material where graphite microstructure is an important consideration, this test method may be used as a reference to concisely define the graphite microstructure required.1.3 These reference photomicrographs are offered primarily to permit accurate reporting of microstructures of cast irons and to facilitate the comparison of reports by different laboratories or investigators.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 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.1.6 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: 646元 加购物车
This specification covers wrought iron-silicon (Fe-Si) relay steels that are generally used in the manufacture of electromechanical devices, such as relays and solenoids, requiring higher electrical resistivity, higher permeability, and lower coercivity and residual magnetism than provided by either carbon steels or soft magnetic low-carbon irons. Available forms and conditions are forging billet, hot-rolled product, cold-finished bars, strip, and wire. These steels are not the same as the flat-rolled non-oriented or grain oriented iron-silicon electrical steels covered by ASTM Specifications A 677, A 683 and A 876. The steels covered in this specification have nominal silicon contents of 1.1, 2.3 and 4.0 % Si. Both the 1.1 and 2.3 % Si types are also available in an enhanced machinability composition. Along with chemical composition, steels produced to this specification must meet a specified maximum value of coercive field strength when heat treated according to this specification. Appendices are given containing typical magnetic, physical and mechanical properties and heat treatment.1.1 This specification covers wrought iron-silicon (Fe-Si) steels that are generally used in the manufacture of electromechanical devices, such as relays and solenoids, requiring higher electrical resistivity, higher permeability, and lower coercivity and residual magnetism than provided by either carbon steels or soft magnetic low-carbon irons. The steels covered in this specification are:Steel Type Nominal Composition 1 1.1 % Si-Fe1F 1.1 % Si-Fe free machining2 2.3 % Si-Fe2F 2.3 % Si-Fe free machining3 4.0 % Si-Fe1.2 This specification covers steels in the form and condition required for fabrication into parts. The fabricated parts typically require a final heat treatment to obtain the desired magnetic performance. The term mill annealed as used in this specification applies to a heat treatment, typically applied by the producer, intended to improve formability. The mill anneal does not provide the optimum magnetic performance and is not intended to replace the need for the finish annealing of parts.1.3 This specification covers steels in the form of forging billets, hot-rolled bar and strip, cold-finished bar, wire, and cold-rolled strip in thicknesses up to 6.35 mm (0.250 in.).1.4 This specification does not cover electrical sheet steels used in transformer and motor laminations. Please refer to Specifications A677, A683, A726, A876, and A1086 for standards pertaining to these material types.1.5 This specification does not cover powder metallurgy materials capable of being processed into magnetic core components having similar silicon contents.1.6 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to customary (cgs-emu and inch-pound) units which are provided for information only and are not considered standard.1.6.1 There are selected values presented in two units, both of which are in acceptable SI units. These are differentiated by the word “or,” as in “μΩ-cm, or, Ω-m.”1.7 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.1.8 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 加购物车