Throught hardening steel
- Carbon low alloy construction steel
- Heat treatable engineering steel
- Case-hardening alloy steel
- Structural alloy spring steel
- Aviation and aero steels
- Boiler alloy and low alloy steel
- Bearing alloy structural steel
- Wear resistance manganese steel - Hadfield steel
- Heat resistant and valve steel
- Structural alloy steel for nitriding
Grades of engineering alloy steel for quenching and tempering
- 1.7033
- AISI 5132
- 30H
- Chromium steel
- Chromium steel
- 1.7034
- AISI 5135
- Chromium steel with reduced carbon, sulfur and phosphorus content
- 1.5711
- 40ChN
- Chromium-nickel steel
- 36NiCr6
- 35NC6
- 1.5710
- 1.5815
- Chromium-nickel steel
- 1.1170
- AISI 1330
- 30Mn5
- 30G2
- Manganese steel
- 37HS
- Chromium-silicon steel
- 30ChGSA
- 30HGSA
- Chromium-manganese-silicon steel
- 1.7734
- Chromium-molybdenum-vanadium steel
- 35ChGSA
- 35ChGS
- Chromium-manganese-silicon steel
- 30ChGSN2A
- 30HGSNA
- Chromium-nickel-silicon-manganese steel
- 1.7218
- AISI 4130
- Chromium-molybdenum steel
- 1.7220
- AISI 4135
- Chromium-molybdenum steel
- 1.7225
- AISI 4140
- Chromium-molybdenum steel
- 1.7228
- AISI 4150
- Chromium-molybdenum steel
- 1.6582
- 817M40
- Chromium-nickel-molybdenum steel
- 1.6511
- Chromium-nickel-molybdenum steel
- 1.6510
- Chromium-nickel-molybdenum steel
- AISI 4340
- 40HNMA
- 1.6565
- 40NiCrMo8-4
- Chromium-nickel-molybdenum steel
- 1.6563
- A320 gr. L43
- Chromium-nickel-molybdenum steel
- 1.6773
- Chromium-nickel-molybdenum steel for most loaded machine parts
- 32NiCrMo12-5
- 1.6655
- Chromium-nickel-molybdenum steel
- Chromium-nickel-molybdenum-vanadium steel for bolts
- 45HNMF
- 45HNMFA
- Chromium-nickel-molybdenum-vanadium steel
- 40ChMFA
- 40H2MF
- 40HMFA
- Chromium-molybdenum-vanadium steel
- 1.6540
- 23MnNiCrMo5-4
- 1.6758
- Steel for chain links
- 1.5752
- 12XН3А
- 12HN3A
- Chromium-nickel steel
- 12H2N4A
- 12Ch2N4A
- 14NiCrMo13-4
- 1.6657
- Chromium-nickel steel
- 20HN3A
- 20ChN3A
- Chromium-nickel steel
- 20H2N4A
- 20Ch2N4A
- Chromium-nickel steel
- 1.6580
- Chromium-nickel steel with molybdenum additive
- 4330 Mod.
- Special heat-treated engineering steel
- AISI 4145H
- Chromium-molybdenum engineering steel
Boron steels
- 1.7182
- Chromium manganese steel with boron addition
- 1.7185
- Chromium manganese steel with boron addition
- 1.5532
- Chromium manganese steel with boron
- 1.7076
- Chromium steel with boron addition
- 1.7077
- Chromium boron steel
- 1.5530
- Manganese steel with boron addition
- 1.5531
- Manganese steel with boron addition
Steels for thermal improvement, i.e. hardening and tempering - characteristics of the material group
The grades of this carbon structural steel feature greater tensile strength, plasticity, crack resistance at dynamic loads, better hardening capacity, and uniform properties across the entire cross section. The group of structural steel alloys with a carbon range of about 0.25-0.50%, which require good mechanical properties with good ductility, and the ability to perform machining after heat treatment.
The heat treatment (+ QT, -T) of the materials consists of a combination of tempering operations at about 800-1000 ℃ and high tempering at about 500-700 ℃, resulting in the formation of a sorbite (ferrite and cementite), thanks to which the material acquires the appropriate qualities. The described structural steels only in improved state achieve their properties in relation to, for example, softened state.
By hardening and tempering, you can obtain parameters which are determined by the chemical composition of the material and the specification. The rule confirms that quality alloy constructional steels should only be used in an improved condition. Products in the described grades are delivered in a softened state (steels for improvement), heat-treated (steels improved thermally), normalized, or raw.
Chemical composition - alloy additives and subgroups
Structural alloys for improvement include in most cases additional or higher concentrations of elements such as Manganese - Mn, Chromium - Cr, Silicon - Si, Nickel - Ni, Molybdenum - Mo, and additionally Tungsten - W, Vanadium - V, and Bor - B, normally not exceeding 4.8%.
On the list of products for improvement, there are also steels for improvements without nickel and molybdenum, such as:
- Chromium-silicon steels (eg. 37HS)
- chromium steels (eg. 30H, 40H, 45H, 38HA)
- manganese steels with improved hardening capacity (eg. 20G2, 30G2, 35G2A,40G2, 45G2),
- Steel with boron addition 27MnCrB5-2, 1.7182, 33MnCrB5-2, 1.7185, 32CrB4, 1.7076, 36CrB4, 1.7077
- abrasion-resistant silico-manganese steels (eg. 37MnSi5, 1.5122 , 40GS, 45SG)
- and chromium-manganese-silicon steels (eg. 20HGS, 25HGS, 30HGSA, 35HGSA, 35HGSNA)
which also has high hardness, tensile strength, yield strength and abrasion resistance without any additional elements. A manganese content of more than 1.8% may reduce the material's ductility, so some of the grades are supplemented with a suitable silicon concentration (35SG, 30HGSA).
Other interesting facts about steel for hardening and tempering
Forging of alloy steels at too high temperatures leads to coarseness and brittleness of the product, while at low temperatures it causes harmful stresses and cracks.
Steels for improvement do not show practically no resistance to atmospheric corrosion. Quite high carbon content, low chromium concentration, and nickel will automatically appear after contact with the outside atmosphere. Products with this composition of elements and structure acts as part of heavily loaded machines and vehicles, such as shafts, gears, axles, bolts, valves, pins requiring high ductility and plasticity.
Among steels for thermal improvement there is also steel for the mining chains 23GHNMA.
Other grades for quenching and tempering: 25H2N4WA, 37HN3A, 38ChN3MFA, 30HN3A, 30ChN2MFA, 65S2WA, 30HGSNA, 35NiCrMoV12-5, 1.6959, 37HGNM
Standards
The above-described steels for thermal improvement of structural alloy steels are defined by the standards PN-72/H-84035, PN-89/H-84030-04, according to which are delivered:
- Seamless tubes for thermal improvement according to PN-70/H-74256, PN-74/H-74207, PN-PN-74/H-74209, PN-EN 10297-1,PN-EN 10305-1
- Rolled sheets for thermal improvement according to PN-75/H-92134, PN-81/H-92129, PN-81/H-92135, PN-EN 10029
- Forgings and forged bars for thermal improvement according to PN-79/H-94500, PN-54/H-94005, PN-84/H-94004, PN-EN 10250-3, PN-EN 10250-2
- Cold-rolled strips for thermal improvement according to, PN-75/H-92335, PN-84/H-92331, PN-67/H-92330, PN-93/H-92329, PN-EN 10132-3
- Rolled bars for thermal improvement according to PN-60/H-93013, PN-87/H-93200, PN-72/H-93202, PN-98/H-93237, PN-56/93223, PN-79/H-93203, Steel FE-PL2108, FEPL2108, EN 2480, PN-67/H-93225, PN-EN 10061, PN-EN 10025-6, and PN-EN 10060, PN-EN 10058, PN-EN 10059,
- Bright and drawn bars for thermal improvement according to PN-85/H-93210, PN-72/H-93208, PN-EN 10278, PN-EN 10277-5, PN-85/H-93210, PN-86/H-93209, PN-52/H-93212
- Wires for thermal improvement according to PN-70/H-92600, PN-75/H-93200, PN-70/H-92608, PN-EN 10263-4, PN-EN 10263-1