Tiêu chuẩn quốc tế
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Số hiệu
Standard Number
ASTM D7474-17
Năm ban hành 2017
Publication date
Tình trạng
A - Còn hiệu lực
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Tên tiếng Anh
Title in English Standard Practice for Determining Residual Stresses in Extruded or Molded Sulfone Plastic (SP) Parts by Immersion in Various Chemical Reagents
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Chỉ số phân loại Quốc tế (ICS)
By field |
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Số trang
Page 4
Giá:
Price Liên hệ / Contact us
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Phạm vi áp dụng
Scope of standard 1.1 This practice covers the evaluation of residual stresses in extruded profile or molded SP parts. The presence and relative magnitude of residual stresses are indicated by the crazing of the specimen part upon immersion in one or more of a series of chemical reagents. The specified chemical reagents were previously calibrated by use of Environmental Stress Cracking (ESC) techniques to cause crazing in sulfone plastics (SP) at specified stress levels. 1.2 This practice applies only to unfilled injection molding and extrusion grade materials of high molecular weight as indicated by the following melt flow rates: PSU 9 g/10 min, max., PESU 30 g/10 m, max, and PPSU 25 g/10 min, max. Lower molecular weight (higher melt flow) materials will craze at lower stress levels than indicated in Tables 1-3. (See Specification D6394 for melt flow rate conditions.) Mixture Mixture Composition Critical Stress, MPa (psi) % by volume Ethanol % by volume Ethyl Acetate 1 50 50 15.2 (2200) 2 43 57 12.1 (1750) 3 37 63 9.0 (1300) 4 25 75 5.5 (800) Mixture Mixture Composition Critical Stress, MPa (psi) % by volume Ethanol % by volume MEK 1 50 50 17.9 (2600) 2 40 60 10.3 (1500) 3 20 80 6.9 (1000) 4 0 100 5.9 (850) Mixture Mixture Composition Critical Stress, MPa (psi) % by volume Ethanol % by volume MEK 1 50 50 22.8 (3300) 2 25 75 13.8 (2000) 3 10 90 9.0 (1300) 4 0 100 8.0 (1150)
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