Xi'An Tiptop Machinery Co., Ltd.
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Cold Weather Service NS-1 High Strength Material AISI4145, AISI 4330V Forging
Dual Chemistry Specification
It allows the use of either AISI 4145 or AISI 4330V as long as all of the requirements are met for the given option. For example, to allow use of AISI 4145, all of the given 4145 requirements need to be met.
Chemical Analysis
The chemical composition shall be determined in accordance with ASTM A751 and shall meet the requirements in weight percent for the specific grade as listed in the table below.
| Grade | C | Si | Mn | P | S | Cr | Mo | Ni (1) (2) | V | Other | |
| 4330V | Min. | 0.28 | 0.15 | 0.60 | - | - | 0.75 | 0.35 | 1.65 | 0.05 | - |
| Max. | 0.34 | 0.35 | 1.00 | 0.025 | 0.015 | 1.10 | 0.50 | 2.30 | 0.10 | 0.40 | |
| 4145 | Min. | 0.43 | 0.75 | 0.80 | 0.15 | ||||||
| Max. | 0.48 | 0.35 | 1.00 | 0.030 | 0.025 | 1.10 | 0.25 | 0.25 | |||
| 4145 Mod | Min. | 0.38 | 0.60 | 0.75 | 0.15 | ||||||
| Max. | 0.49 | 0.40 | 1.25 | 0.030 | 0.025 | 1.50 | 0.75 | 0.25 |
Mechanical Properties
The surface hardness shall be as listed below as measured by ASTM E18 or E10. The mechanical properties shall be referenced from the relevant Engineering drawing determined at the approximate mid-radial location in accordance with ASTM A370 and shall be within the following ranges.
| Minimum yield as referenced from the Engineering Drawing 0.2% Proof Stress ksi | Mid Radial Mechanical Properties | |||||
| 0.2% Proof Stress, ksi (N/mm2) | Tensile Strength, ksi (N/mm2) | Elongation % | Reduction of Area, % | Hardness, HRC (BHN) | ||
| 140 | Min. | 140 (966) | 165 (1172) | 15 | 45 | 36 (336) |
| Max. | - | 190 (1310) | - | - | 42 (390) | |
| 130 | Min. | 130 (897) | 160 (1103) | 15 | 45 | 34 (321) |
| Max. | - | 180 (1241) | - | - | 40 (375) | |
| 120 | Min. | 120 (828) | 150 (1034) | 15 | 45 | 32 (302) |
| Max. | - | 170 (1172) | - | - | 38 (352) | |
| 110 | Min. | 110 (759) | 140 (966) | 15 | 45 | 30 (285) |
| Max. | - | 160 (1103) | - | - | 36 (331) | |
The absorbed impact energy shall be determined at the temperatures indicated using the Charpy V-notch method in accordance with ASTM E23. For cold weather service Charpy’s shall meet the requirements when tested at -40°C(-40°F)
| Temp | Charpy Ave 3 | No Single Value Below | # specimens below min Ave | |
| Ambient (20 Deg C) | Min | 40 ft. lbs (54J) | 36 ft. lbs (47J) | 1 only |
| -40 Deg C | Min | 40 ft. lbs (54J) | 36 ft. lbs (47J) |
Through Thickness Hardness Testing in accordance with NS-1
Prior to purchase, bars will be subjected to a through thickness 12 point Hardness test with no values having a hardness differential greater than 6RC points. This is to be done in accordance with the requirements of NS-1 specification for Drill Stem Substitutes.
