ASTM C750-2018 pdf free download

ASTM C750-2018 pdf free download.Standard Specification for Nuclear-Grade Boron Carbide Powder
1. Scope
1.1 This specification defines the chemical and physical requirements for boron carbide powder intended for a variety of nuclear applications. Because each application has a differ- ent need for impurity and boron requirements, three different chemical compositions of powder are specified. In using this specification, it is necessary to dictate which type of powder is intended to be used. In general, the intended applications for the various powder types are as follows: 1.1.1 Type 1—For use as particulate material in nuclear reactor core applications. 1.1.2 Type 2—Powder that will be further processed into a fabricated shape for use in a nuclear reactor core or used in non-core applications when the powder directly or indirectly may cause adverse effects on structural components, such as halide stress corrosion of stainless steel. 1.1.3 Type 3—Powder that will be used for non-core appli- cations or special in-core applications. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Terminology
3.1 Definitions ofTerms Specific to This Standard: 3.1.1 buyer—organization issuing the purchase order. 3.1.2 powder lot—that quantity of boron carbide powder blended together such that samples taken in accordance with the procedures of8.1 can be considered as representative ofthe entire powder lot. 3.1.3 seller—boron carbide powder supplier.
4. Ordering Information
4.1 The buyer may specify the following information on the order: 4.1.1 Quantity (weight of delivered product). 4.1.2 Nominal particle size, particle size range, and appli- cable tolerance. 4.1.3 Density and method of measurement. 4.1.4 Angular or spherical shape. 4.1.5 Shape factor. 4.1.6 Lot size.
5. Chemical Composition
NOTE 1—B 4 C powder is hygroscopic and certain applications require low-moisture content. 5.1 The material shall conform to the chemical composition requirements prescribed in Table 1 (see Methods C791). 5.2 When agreed upon between the buyer and the seller, the weight loss of the powder shall not exceed 1 % when heated at 110°C for 1 h in air.
6. Physical Requirements
6.1 The nominal particle size, particle size range, and applicable tolerances shall be agreed upon between the buyer and the seller. Method C371 and E11 shall be applied for particles larger than or equal to 75 µm. For particles smaller than 75 µm, the particle size distribution shall be determined by method B822. 6.2 The density shall be determined when specified. The Tap-density (Test Method B527) or Skeletal Density (Test Method B923) are approved methods. The recommended value to be used for the theoretical density of stoichiometric B 4 C of natural isotopic content is 2.52 g/cm 2 . 6.3 When specified, the angular or spherical shape shall be determined utilizing a method agreed upon between the buyer and the seller. 6.4 When specified, the shape factor shall be determined utilizing a method agreed upon between the buyer and the seller.
10. Rejection
10.1 Unless the buyer and seller agree otherwise, rejection and acceptance shall be on a powder lot basis. 10.2 Powder lots that fail to conform to the requirements of this specification may be rejected by the buyer. The seller may petition the buyer to waive selected requirements for identified out-of-specification lots. Decision to grant such waiver belongs to the buyer. The buyer shall approve, prior to use, any remedy proposed to bring rejected lots into specification. 10.3 In the event of disagreement over the results of chemical analysis, samples shall be submitted to a mutually selected referee for resolution.