W. NR. 1.2379
Characteristics
Chrome-molybdenum-vanadium steel with big hardenability for hardening in oil and in air, especially high resistance to the wear (higher than by 1.2080), good cutting power, very good firmness in the pressure, lower toughness (but higher than by 1.2080). This steel shows good dimensional stability at the heat treatment, suitable for hardening to the secondary hardness (the possibility of nitriding). Further the steel is very difficult to sharpen, it works at the heat with difficulties and has a rather difficult workability in the annealed state.
Suitability
Tools for cold cutting, i.e. all kinds of tools with the long durability for cutting on presses and punching of materials of smaller thicknesses and materials of high hardness (especially difficult-shape tools for cutting, e.g. transformer metal sheets and metal sheets from stainless steels), knives for plate shears for the sheet and strip steel up to thickness of 10 mm of sheared material, knives for wire cutting etc. Tools for mechanical working such as e.g. smaller girders and tools for drawing, all kinds of tools for transformation and punching of materials. Further the steel is suitable for simple and symmetric tools for pressing and pushing, tools for thread rolling, plain and profile rolls, swages and also for cold work. Cutting tools such as broaching thorns, profile knives and difficult-shape milling machines for lower cutting speeds and for treatment of nonmetallic abrasive materials. Further the steel is applied in the production of highly stressed molds and their components for working of plastic and powder substances, glass, porcelain and ceramic materials. By tools for crushing and grinding it is used for hammers of crushers and jaws for mild grinding and crushing.
Chemical composition of steel W.Nr. 1.2379
| Steel grade | Chemical composition in % | Hardness in the state | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| soft-annealed | heat-treated | ||||||||||||
| C | Mn | Si | Cr | W | Mo | V | Ni max | Co | P max. | S max. | HB max. | HRC min. | |
| DIN X155CrVMo121 | 1,50-1,60 | 0,15-0,45 | 0,10-0,40 | 11,0-12,0 | 0,60-0,80 | 0,90-1,10 | 0,030 | 0,030 | 255 | 59 | |||
| ČSN 19 573 | 1,40-1,60 | 0,20-0,45 | 0,20-0,45 | 11,0-12,5 | 0,60-0,95 | 0,80-1,20 | 0,030 | 0,035 | 250 | 63 | |||
Heat treatment of steel W.Nr. 1.2379
| Way | Temperature [°C] | Procedure | |
|---|---|---|---|
| Forging | 850-1050 | Cool slowly in calm air or better e.g. in dry ash or other thermally-insulated material | |
| Soft annealing | 830-860 | Warm few hours (according to the size of object), mostly four hours are enough and cool slowly in oven | |
| Annealing to lower tension | 600-650 | Warm 1 to 2 hours and cool slowly in the furnace | |
| Hardening | 1000-1080 | Cool in oil, air or salt bath at the temperature of about 500-550°C | |
| Tempering | 100-550 | Cool in air, the degree of tempering is set by hardness and toughness of instrument according to the tempering chart | |
Note
- Hardening temperature 1000-1050 °C
Chart of tempering values depending on the hardness:
| °C | 100 | 200 | 300 | 400 | 500 | 525 | 550 | 600 |
|---|---|---|---|---|---|---|---|---|
| HRC | 63 | 61 | 58 | 58 | 58 | 60 | 56 | 50 |
Graph
Note
- Hardening temperature 1050-1080 °C, tempered 3 times
Chart of tempering values depending of the hardness:
| °C | 100 | 200 | 300 | 400 | 500 | 525 | 550 | 600 |
|---|---|---|---|---|---|---|---|---|
| HRC | 61 | 60 | 58 | 59 | 62 | 62 | 57 | 50 |
Graph
Product range
Round bars: D10 - D603
Blocks: 455x605, 305x805
Flat bars: from 10x605 to 255x605
We will deliver any semi-finished products from the above mentioned dimensions. Other dimensions, except for given stock supplies, have to be consulted with us.
