مهره A 194 و استاندارد های آن | ASTM A194
استاندارد ASTM A194 شامل مهره های کربنی ، آلیاژ و فولااد ضد زنگ هستند که برای شرایط با فشار یا دمای بالا در نظر گرفته می شود.
در جداول پایین کلاس ها و مشخصات مکانیکی و شیمیایی انواع مهره های ASTM A194 بطور کامل ذکر شده اند.
کلاس های مهره A194
2 | Carbon steel heavy hex nuts |
---|---|
2H | Quenched & tempered carbon steel heavy hex nuts |
2HM | Quenched & tempered carbon steel heavy hex nuts, 100% hardness tested |
4 | Quenched & tempered carbon-molybdenum heavy hex nuts (withdrawn in 2017) |
7 | Quenched & tempered alloy steel heavy hex nuts |
7M | Quenched & tempered alloy steel heavy hex nuts, 100% hardness tested |
7L | Quenched & tempered alloy steel heavy hex nuts, Charpy impact tested |
8 | Stainless AISI 304 heavy hex nuts |
8M | Stainless AISI 316 heavy hex nuts |
خواص مکانیکی مهره A 194
A194 Mechanical Properties
Grade Identification Marking5 | Specification | Material | Nominal Size, In. | Tempering Temp. °F | Proof Load Stress, ksi | Hardness Rockwell | See Note | |
---|---|---|---|---|---|---|---|---|
Min | Max | |||||||
ASTM A194 Grade 2 | Medium Carbon Steel | 1/4 – 4 | 0 | 150 | 159 | 352 | 1,2,3 | |
ASTM A194 Grade 2H | Medium Carbon Steel, Quenched and Tempered | 1/4 – 4 | 850 | 175 | C24 | C38 | 1,2 | |
ASTM A194 Grade 2HM | Medium Carbon Steel, Quenched and Tempered | 1/4 – 4 | 1150 | 150 | 159 | 237 | 1,2,3 | |
ASTM A194 Grade 4 | Medium Carbon Alloy Steel, Quenched and Tempered | 1/4 – 4 | 1100 | 175 | C24 | C38 | 1,2 | |
ASTM A194 Grade 7 | Medium Carbon Alloy Steel, Quenched and Tempered | 1/4 – 4 | 1100 | 175 | C24 | C38 | 1,2 | |
ASTM A194 Grade 7M | Medium Carbon Alloy Steel, Quenched and Tempered | 1/4 – 4 | 1150 | 150 | 159 | 237 | 1,2,3 | |
ASTM A194 Grade 8 | Stainless AISI 304 | 1/4 – 4 | – | 80 | 126 | 300 | 4 | |
ASTM A194 Grade 8M | Stainless AISI 316 | 1/4 – 4 | – | 80 | 126 | 300 | 4 | |
NOTES
Inch Fastener Standards. 7th ed. Cleveland: Industrial Fasteners Institute, 2003. N-80 – N-81. |
خواص شیمیایی مهره های A 194
A194 Chemical Properties
Element | 2, 2H, and 2HM | 4 | 7 and 7M (AISI 4140) | 8 (AISI 304) | 8M (AISI 316) |
---|---|---|---|---|---|
Carbon | 0.40% min | 0.40 – 0.50% | 0.37 – 0.49% | 0.08% max | 0.08% max |
Manganese | 1.00% max | 0.70 – 0.90% | 0.65 – 1.10% | 2.00% max | 2.00% max |
Phosphorus, max | 0.040% | 0.035% | 0.035% | 0.045% | 0.045% |
Sulfur, max | 0.050% | 0.040% | 0.040% | 0.030% | 0.030% |
Silicon | 0.40% max | 0.15 – 0.35% | 0.15 – 0.35% | 1.00% max | 1.00% max |
Chromium | 0.75 – 1.20% | 18.0 – 20.0% | 16.0 – 18.0% | ||
Nickel | 8.0 – 11.0% | 10.0 – 14.0% | |||
Molybdenum | 0.20 – 0.30% | 0.15 – 0.25% | 2.00 – 3.00% |