Stål Typer
Manglende stål type angivelse på tegninger er ofte årsag til misforståelser.
Vi anbefaler specifikationer oplyst af stålgrossister og ikke producenter af pro- dukter.
Specifikationerne nedenfor er fra en britisk grossist, gældende i Kina.
Betegnelsen rustfast stål anvendes i flæng. Der er en udbredt norm der siger Crom indholdet skal være større end
11,5% - 12% inden betegnelsen rustfast stål reelt er gældende.
A2 tool steel
A2 tool steel is an air hardening, cold work steel. A2 is a 5% Chromium steel which provides high hardness after heat treatment with good dimensional stability. It is heat treatable and will offer a hardness in the range 57-62 HRC.
The lower chromium content in A2 tool steel means that it does not provide the same wear and abrasion resistance shown by D2 and D3, However, it is more easily machined and will hold a good edge.
A2 delivers good toughness with medium wear resistance and is relatively easy to machine. Used in many applications which require good wear resistance as well as good toughness.
Typical Applications for A2 Steel:
blanking tools
punch dies
trim dies
forming dies
gauges
shear blades
stamping dies
AISI A2 equivalent grades: BS4659 - BA2, AISI - A2, DIN - 1.2363 - X100CrMoV5
Typical chemical composition of AISI A2 Tool Steel |
|||||
|---|---|---|---|---|---|
| C | Mn | Cr | Ni | Mo | V |
| 1.00% | 1.0% | 5.00% | 0.30% | 1.0% | 0.15-0.5% |
Forging:
Heat the A2 slowly to 700°C then more rapidly to 1050-1100°C. Avoid working below 900°C. Reheat as often as necessary to maintain proper forging temperature. After forging cool very slowly.
Annealing:
Soak thoroughly at 840-850°C, then slowly furnace cool at a rate of not more than 20°C per hour. After annealing A2 a maximum hardness of 215 Brinell may be achieved.
Stress relieving:
After heavy grinding or machine it is advisable to stress relieve A2 to reduce the danger of cracking or distortion during subsequent heat treatments. Heat slowly to 670-700°C, soak for a minimum of two hours per 25mm of section then cool down in the furnace.
Hardening:
Pre heat slowly to 600-700°C and soak. Continue heating to the final hardening temperature of 950/980°C and allow the component to equalise. Quench in oil or cool in air.
Tempering:
Heat uniformly and thoroughly to the desired temperature and hold for 25 minutes per cm of thickness. A2 tool steel can be double tempering, after intermediate cooling to room temperature. Temper at 200°C for a balance of hardness and strength or 350°C where strength is more important than hardness.
Tempering A2 tool Steel |
||||||
|---|---|---|---|---|---|---|
| Tempering °C |
150 |
200 |
250 |
300 |
350 |
400 |
| HRC |
62/61 |
61/60 |
60/59 |
59/58 |
58/57 |
58/57 |
D2 (A4) steel
D2 tool steel is an air hardening, high-carbon, high-chromium tool steel. It has high wear and abrasion resistant properties. It is heat treatable and will offer a hardness in the range 55-62 HRC, and is machinable in the annealed condition. D2 steel shows little distortion on correct hardening. D2 steel’s high chromium content gives it mild corrosion resisting properties in the hardened condition.
If you need better machinability then consider A2 tool steel which has a chromium content of 5% and is more readily machinable.
Typical applications for D2 Steel:
- Stamping or Forming Dies
- Punches
- Forming Rolls
- Knives, slitters, shear blades
- Tools
- Scrap choppers
- Tyre shredders
Typical chemical composition of AISI D2 Steel |
||||
|---|---|---|---|---|
|
C |
SI |
Cr |
Mo |
V |
| 1.50% | 0.30% | 12.00% | 0.80% | 0.90% |
Forging:
Heat slowly and uniformly to 700°C then more rapidly to 900/1040°C. Do not continue to forge D2 below 925°C. Reheat as often as necessary to maintain proper forging temperature. After forging cool slowly. This is not an annealing process. After the forging is cold, it must be annealed as described below.
Annealing:
Heat uniformly to 843/871°C, then slow furnace cool at a rate of not more than 10°C per hour. After annealing D2 a maximum hardness of 240 Brinell may be achieved
Hardening:
D2 tool steel is extremely sensitive to overheating during hardening – do not overheat.
Pre heat slowly to 750/780°C and soak. Continue heating to the final hardening temperature of 1000/1030°C and allow the component to equalise. Quench in oil or cool in air.
Tempering:
Heat uniformly and thoroughly to the desired temperature and hold for 25 minutes per cm of thickness. D2 can be double tempering at approximately 15°C below the first tempering, after intermediate cooling to room temperature.
303 Stainless Steel
303 stainless steel is the most readily machineable of all the austenitic grades of stainless steel.
303 stainless steel owes its machineable nature to the presence of Sulphur in the composition. However, it should be noted that the Sulphur also decreases the corrosion resistance of the steel and slightly lowers its toughness. The toughness is still excellent as with other austenitic grades. AISI 304 stainless steel offer higher corrosion resistance than 303.
All stainless stock can be delivered mirror polished if required
| BS 970 1991 | AISI/SAE | Werkstoff |
| 303S31 | 303 | 1.4305 |
304 Stainless Steel
We are suppliers of 304 and 304L Stainless Steel in a wide range of bar, flat, sheet, plate, angle and seamless tubing and pipes. Reliable local and nationwide delivery.
Stainless steel types 304 and 304L. Type 304 is the most versatile and widely used stainless steel. It is also known as 18/8 from the nominal composition of type 304 being 18% chromium and 8% nickel.
The most versatile and widely applied of the 300 series Stainless Steels. It has excellent forming and welding characteristics. AISI 304 stainless can be deep drawn more severely than Types 301 and 302 without immediate heat softening, a characteristic that has made this grade dominant in the manufacture of drawn stainless steel parts such as sinks, splashbacks and saucepans.
Type 304 stainless steel also has outstanding welding characteristics. Post-weld annealing is not required to restore the excellent performance of this grade in a wide range of mildly corrosive conditions.
Type 304L does not require post-weld annealing and finds extensive use in heavy gauge components where freedom from carbide weld precipitation is often required.
All stainless stock can be delivered mirror polished if required
| BS 970 1991 | AISI/SAE | Werkstoff |
| 304S11 | 304L | 1.4306 |
| 304S15 | 304 | 1.4301 |
316 Stainless Steel
316 Stainless Steel - used for food and surgical stainless steel. Also known as marine grade stainless steel due to its increased resistance to chloride corrosion compared to type 304. 316L is an extra low carbon grade of 316, generally used in stainless steel watches. Its resistance to chloride attack means it is often selected for use in marine atmospheres. 316Ti includes titanium for heat resistance, therefore it is used in flexible chimney liners.
316 stainless steel is a molybdenum-bearing grade. This addition gives the better overall corrosion resistance properties than type 304 and higher creep strength at elevated temperatures.
All stainless stock can be delivered mirror polished if required
| BS 970 1991 | AISI/SAE | Werkstoff |
| 316S11 | 316L | 1.4404 |
| 316S13 | 316L | 1.4435 |
| 316S31 | 316 | 1.4401 |
| 316S33 | 316 | 1.4436 |
410 Stainless Steel
410 stainless steel is the basic martensitic stainless which will attain high mechanical properties after heat treatment. It has good impact strength, corrosion and scaling resistance up to 649°C. Its strength, good ductility and resistance to corrosion in mild atmospheres, steam and mild chemical environments make it well suited for highly stressed parts.
Commonly used in vehicle exhausts, manifolds and high temperature engine components, medical instruments and devices and petro-chemical applications.
All stainless stock can be delivered mirror polished if required
| BS 970 1991 | AISI/SAE | Werkstoff |
| 410S21 | 410 | 1.4006 |
