1. Product use:
420U6 is a new type of martensitic stainless steel obtained by reducing carbon content and increasing nitrogen content on the basis of traditional martensitic stainless steel 420J1. This steel achieves high hardness and corrosion resistance better than 420J1. After heat treatment, 420U6 can be used for parts that bear higher stress, such as valves and fasteners, and can also be used to manufacture various types of knives, such as table knives, hardware knives, etc.
2. Chemical composition:
The chemical composition of 420U6 is shown in Table 1:
Table 1 Chemical composition of 420U6/%
| Chemical Element | C | Si | Mn | P | S | Cr | Ni | N |
|---|---|---|---|---|---|---|---|---|
| Range | 0.13~0.25 | ≤1.00 | ≤1.00 | ≤0.045 | ≤0.03 | 12.0~14.0 | ≤0.6 | 0.06~0.15 |
| Control value | 0.14~0.18 | 0.43~0.65 | 0.50~0.65 | 0.20~0.25 | 0.002~0.004 | 12.5~13.5 | 0.20~0.35 | 0.067~0.10 |
3. Product performance:
The annealed mechanical properties of the hot-rolled sheet and the hardness after quenching are shown in Table 2.
Table 2 Mechanical properties of finished products
| Grade | Specification (mm) | Rp0.2(Mpa) | Rm(Mpa) | A(%) | HRB | Horizontal Ak (half sample) J | Hardness after quenching (HRC) |
|---|---|---|---|---|---|---|---|
| 420U6 | 8.0 | 355 | 625 | 30.5 | 84 | 70 | 52 |
| 420J1(Comparative material) | 8.0 | 420 | 665 | 24 | 90 | 55 | 46 |
It can be seen that 420U6 can achieve lower annealing strength and higher elongation, and at the same time can obtain higher quenching hardness. The hardness study after quenching believes that the hardness after treatment can reach the performance of 3Cr13, which can completely replace the use of 3Cr13 materials on cutting tools.
4. Corrosion resistance:
Because 420U6 contains more N than 420J1, its pitting resistance is improved. In the comparative salt spray corrosion resistance test of 420U6 and 420J1, it can be clearly seen that the salt spray corrosion resistance of 420U6 steel is better than that of 420J1 steel.
5. TISCO can produce specifications and delivery status:
- Delivery specifications:
Hot-rolled steel strip: （3.0~8.0）×（1000~2000）×C(mm) (delivery with trimmed or burr)
- Delivery status:
TISCO can now produce hot-rolled black-skinned and hot-rolled pickled 420U6 stainless steel coils. And prepare to develop 2B surface cold plate products. ”