24 July 2021 Hardware Tool Steel Sheet
Cr2 Hardware Tool Steel Sheet
Cr2 alloy tool steel is widely used as measuring tools, such as templates, pallets, sample sets, gauges, block gauges, ring gauges, threaded plug gauges and sample columns, etc., and can also be used to manufacture cold work molds such as wire drawing dies and cold heading dies, and Low-speed tools cut materials that are not too hard. Cr12 is a tool steel for measuring tools and cutting tools. The composition of this steel is equivalent to that of GCr15 bearing steel. Its hardenability, hardness and wear resistance are higher than that of carbon tool steel, and its size changes during heat treatment are not large.
Dimensional Range of CR2 Steel:
CR2 Steels is available from thickness range 0.25 mm to 4.0 mm. The width is usually 950 mm, 1219 mm, 1500 mm and 2000 mm.
Chemical Composition of CR2 Steel:
The chemical composition of CR2 Steels is comprised 0.12 percent of Carbon maximum, 0.5 percent of manganese maximum, 0.035 percent of Sulphur maximum, 0.05 percent of Phosphorous maximum, and remaining percentage is of iron (Fe) with negligible impurities.
Mechanical Properties of CR2 Steel:
The mechanical properties of CR2 Steels are comparable to SPCD steels, but unlike the JIS G3141 standard, the ISO 3574 standard does not identify the minimum tensile strength but it identifies the maximum range. The maximum yield strength is 240 MPa, the tensile strength is 370 MPa and minimum elongation is 31 percent. The hardness is 65 HRB maximum.
Chemical Composition:
Sulfur S: ≤0.030
Phosphorus P: ≤0.030
Chromium Cr: 1.30～1.65
Nickel Ni: allowable residual content ≤0.25
Copper Cu: allowable residual content ≤0.30
Equivalent Grade:
Chinese GB/JB label: Cr2
Japanese JIS mark: SUJ2
American AISI label: L3
American ASTM label: L3
German DIN steel number designation: 105Cr6
German DIN material number: 1.2067
ISO label: 100Cr2
Taiwan CNS label: SUJ2
British BS mark: BL1/BL3
French AFNOR label: Y100C6 (NF)
Process Specification:
Critical point temperature
(Approximate value) Ac1 =745°C, Ar1 =710°C, Accm =900°C, Ms=140 ~180°C.
General softening specification for cold pressed blanks
The softening temperature is 820±10℃, keep it for 3~4h, and then slowly furnace-cooled to ≤650°C at a cooling rate of 5°C/h, and then air-cooled out of the furnace.
Normalizing norms
- Normalizing temperature 900~920°C, holding time: salt bath furnace 25~30s/mm, empty furnace 70~90s/mm, air cooling, hardness 302-388HBW.
- Normalizing temperature 930~950°C, holding time: salt bath furnace 25~30s/mm, empty furnace 70~90s/mm, air cooling, hardness 302 ~388HBW.
Annealing specification
Annealing temperature is 770~790°C, holding for 2~4h, and then at a cooling rate of 30°C/h, the furnace is slowly cooled to 500~600°C, and the furnace is air cooled.
Specification for isothermal spheroidizing annealing
- 790~720°C ×2 -3h, furnace cooling, 700 ~720°C ×3 ~4h, then out of the furnace and air cooling, hardness ≤229HBW, pearlite structure 2 -5, network carbide grade ≤2.
- 770~790°C ×2~4h, furnace cooling, 680~700°c ×4~6h, furnace cooling to 500~600°C, air cooling after furnace, hardness 179~229HBW.
Specification for isothermal spheroidization and softening of cold pressed blanks
(820±10) °C×3 ~4h, furnace cooling, (720±10) °C ×6 -8h, then slowly cooled to ≤600°C, out of the furnace, air cooling, after treatment, the hardness is reduced from ≤229HBW to ≤179HBW .
Quenching and tempering treatment specification
Quenching temperature 840~860°C, oil cooling, tempering temperature 660~680°C, hardness 229HBW.
Quenching and tempering specifications
Quenching temperature 830~860°C, oil cooling, hardness ≥62HRC, tempering temperature 160~170°C or 200~250°C.
Application:
Commonly used for cold rolling rolls and cold rolling rolls.
After the φ30mm roll is heated and quenched in a salt bath, its hardness value is related to the pretreatment process of the blank. The quenching hardness of the original annealed blank is 65~66.5HRC; the quenching hardness of the quenched and tempered blank is 66~67HRC, and the hardness value is relatively uniform, without quenching cracking.
The cold stamping die and the precision pressing zygomatic cold extrusion die made of this steel are tempered by pumping to pumping, and the toughness is good.
The steel can be used as a punching die and cold heading die in the bearing industry; in the metallurgical industry, it can be used as a rolling die and cold drawing die for straightening profiles with better results.
After using this steel punch with carbide refinement treatment, then quenching and tempering, the hardness is 59~60HRC, and its unnotched impact toughness can reach 15J/cm, which is more than double the conventional treatment, and it will also make the mold The service life is increased by more than 10 times.
It is used for various cold stamping dies in small and medium production batches, as well as integral cold heading dies, punching and shearing tools that need to be used in the hardened state of the thin shell.
The small mold adopts martensite graded quenching and austempering process, which has good strength and toughness.
Large size cold die can be made.
After the large and medium-sized molds are quenched, a thin shell is formed and hardened, which has good impact fatigue resistance.
Used to make measuring tools, such as templates, gauges, block gauges, ring gauges, threaded plug gauges, sample columns, pallets, sample sets, etc.
Cold working dies such as wire drawing dies and cold heading dies can be made dry.
It is mostly used for cutting tools with low speed, small feed, and not very hard materials, such as turning tools, slotting tools, milling cutters, reamers, etc.
Used for small and medium-sized plastic molds that are not very complicated.