AISI D7 Tool Steel
- Model
- D7
Item specifics
- Process
- hot rolled or hot forged
- Delivery Condtion
- annealed
- Surface Condition
- smooth, bright
Review
Description
AISI D7 Tool Steel
D7 tool steel is a high-carbon, high-chromium air-hardening tool steel that exhibits exceptional wear resistance. The high carbon and vanadium contents result in numerous, hard vanadium carbide particles in the steel. These carbides exhibit a hardness that is equivalent to approximately 80 to 85 Rockwell C.
The following are the list of applications of D7 tool steels:
l Brick mold liners
l Powder compaction tooling
l Shot blasting equipment liners
l Flattening rolls
l Powder compaction tooling
l Tools for ceramic extrusion and molding.
Designations:
ASTM A681-US
FED QQ-T-570-US
SAE J437-US
SAE J438-US
UNS T30407-US
AISI D7 Tool Steel-US
Chemical composition(mass fraction)(wt.%) of the D7
C(％) | Si(％) | Mn(％) | P(％) | S(％) | Cr(％) | Mo(％) | V(%) |
2.15～2.50 | 0.10～0.60 | 0.10～0.60 | ≤0.030 | ≤0.030 | 11.5～13.5 | 0.70～1.20 | 3.80～4.40 |
MECHANICAL PROPERTIES
Yield | Tensile | Impact | Elongation | Reduction in cross section on fracture | As-Heat-Treated Condition | Brinell hardness (HBW) |
984 (≥) | 682 (≥) | 41 | 31 | 23 | Solution and Aging, Annealing, Ausaging, Q+T,etc | 322 |
Forging/Rolling:
Preheat to 1500° F and soak thoroughly. Then raise to 2050° F - 2125° F. Do not forge or roll below 1800° F, cool slowly from the forging or rolling temperature. Do not normalize.
Annealing:
Heat slowly to 1600° F - 1650° F, and hold for uniformity, furnace cool at a rate of 20° F per hour to 1000° F then air cool. Expect Brinell hardness 235 - 262.
Hardening:
Preheat to 1500° F and soak until uniformly heated and either transfer or raise furnace temperature to 1850° F - 1950° F, and hold 1 hour per inch of greatest thickness. Cool in still air.
Tempering:
Temper immediately after quenching, before part has cooled to below 150° F. Parts should be held a minimum of 2 hours per inch of greatest thickness. Double tempering is recommended. For maximum wear resistance temper at 300° F. The above tempering table may be used as a guide. However, since 1/2" dia. specimens were used for this test, it may be found that heavier sections are several points lower.
