Q: A customer has asked whether we can supply carbon and alloy steel valve bodies meeting Supplemental Requirement S23 in ASTM A What is the. fication, shall apply to steel castings for pressure-containing Specification A and SI units for material ordered to parts under each of the following ASTM. Buy ASTM A /AM: SPECIFICATION FOR STEEL CASTINGS, GENERAL REQUIREMENTS, FOR PRESSURE-CONTAINING.
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Variables That Influence Embrittlement There are a number of variables that influence the potential for this type of embrittlement: The mechanical test methods and definitions are presented in details. These are provided for use when additional testing or inspection is desired and apply only when specified individually by the purchaser in the order.
A cross-section of the heaviest section of a sacrificial casting A coupon attached to the heaviest section A coupon removed from directly under a riser or A coupon from the same heat of material removed from a separately cast test block with a thickness representative of the heaviest section of the casting.
Emerson Completes Acquisition of iSolutions Inc. E Reference Radiographs for Heavy-Walled to 12 in. This abstract is a brief summary of the referenced standard.
Although some foundries monitor nitrogen levels in their steel, many do not have the necessary equipment to do this.
Astk does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
One tension test shall be made from each heat, and shall conform to the tensile requirements specified. The macroetch test specified in Supplemental Requirement S23 in ASTM A is designed to detect the occurrence of aluminum nitride embrittlement in castings.
Certain elements are known to inhibit the formationof aluminum nitride. A complex casting with relatively thin walls may experience slower cooling rates than a simple casting with the same wall thickness because the complex casting will lose heat through the mold less effectively. ViewIn Technology for Mechanical Seals. Historical Version s – view previous versions of standard. The resulting etched specimen is compared with 10 reference macrographs.
Combining values from the two zstm may result in nonconformance with the standard.
When the metal is poured into the casting mold, the oxygen can come out of the solution and form gas porosity in the castings. Therefore, the nitrogen content of the steel is often not known or reported, and it is possible that enough nitrogen is present to form aluminum nitride.
Steel Castings, Martensitic Stainless and Alloy, for. The thickness of the casting orportion of the casting is an obviousfactor influencing whether embrittlementoccurs, since thicker casting sectionswill cool more slowly through thecritical temperature range than thinsections. When steel is melted, oxygen and nitrogen can be dissolved in the molten steel.
Texas Manufacturing Expands Modestly, Outlook. Ferritic and martensitic steel shall be cooled after pouring to provide substantially complete transformation of austenite prior to heat treatment to enhance mechanical properties. Adtm values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Custom Hydraulic Power Units. Upcoming Valve Industry Events Reprints.
The a03 shall be made by open-hearth or electric-furnace process, with or without separate refining such as argon-oxygen-decarburization AODunless otherwise designated by the individual specification. E Reference Radiographs for Heavy-Walled 2 to in. Link to Active This link will always route to the current Active version of the standard.
Supplemental Requirement S23 in ASTM A
Test coupons shall be cast from the same heat as the castings represented, except that for investment castings, the test coupons shall be cast in the same type of mold as the castings.
The fracture is often very shiny due to the presence of aluminum nitride platelets on the surface. Admiral Valve Announces Partnership with Diek. One of the elements that is sometimes added as a deoxidizer is aluminum, which creates a potential for the formation of aluminum nitride.
New Washer Application Search Tool. An analysis of each heat shall be made by the manufacturer to determine the percentages of the elements specified.
Most foundries have the equipment necessary to analyze and report aluminum content.
Stainless Steel, for Pressure-Containing Parts. Castings, Austenitic, for Pressure-Containing. Heats with severity levels 4 and lower are acceptable. The casting configuration can also influence the cooling rate.
The presence of these elements results in the formation of oxide compounds, which mitigates the formation of oxygen gas bubbles during solidification. The specifications for the common cast steels used in valve bodies do not require analysis or reporting of nitrogen as a standard requirement.