1.5528
22MnB5
Boron-alloyed heat-treatable steel with high hardenability and widespread use in press-hardening and wear-loaded parts.
Complete introduction and metallurgical analysis
1.5528 / 22MnB5 belongs to Boron Steels and selection centres on cost-effective hardenability created by a controlled small boron addition.
Boron-alloyed heat-treatable steel with high hardenability and widespread use in press-hardening and wear-loaded parts.
The principal recorded elements are C≈0.22%, Si≈0.4%, Mn≈1.25%, P≈0.025%, S≈0.015%, Cr≈0.4%, B≈0.0029%. Mid-range values support engineering interpretation and do not replace purchase limits.
The expected microstructure is tempered martensite after an appropriate hardening cycle, subject to boron control and prior-austenite condition; delivery condition, section size, melt quality and processing history can change that state.
Comparison indices are hardness 55/100, toughness 62/100, impact 63/100, wear 51/100 and bending 75/100. These are internal indices, not standard test results.
The screening temperature range is 180–350 °C; strength or hardness loss, oxidation, exposure time and creep must be assessed separately.
A representative process route is forming or press hardening followed by controlled quenching and tempering where required. Obtain actual temperatures, times and cooling media from the grade and product data sheet.
Manufacturing indices are weldability 57/100, machinability 62/100, corrosion resistance 16/100 and fatigue resistance 60/100; use them for screening only.
The principal risk is variable hardenability if boron is not effective or if the heat-treatment and austenite condition are poorly controlled. Evaluate geometry, surface condition, environment and the governing failure mechanism together.
A similar name or calculated relationship is not proof of interchangeability; match chemistry, specification, condition, heat treatment and MTC.
Engineering conclusion: 1.5528 / 22MnB5 is a rational candidate when useful through-hardening response with relatively economical alloy content matches the real load, environment and certified product condition.
International equivalents and designations
A close counterpart is not automatically interchangeable. Confirm chemistry, product standard, delivery condition, dimensions and heat treatment.
Chemical composition and the role of each element
The principal recorded elements are C≈0.22%, Si≈0.4%, Mn≈1.25%, P≈0.025%, S≈0.015%, Cr≈0.4%, B≈0.0029%. Mid-range values support engineering interpretation and do not replace purchase limits. Composition is shown for screening and traceability. The current purchase standard and the heat-specific MTC remain authoritative.
| Element | Weight-percent range | Metallurgical role and effect |
|---|---|---|
| C | 0.19–0.25 % | Carbon raises hardness, strength and carbide potential; excessive carbon can reduce toughness and weldability. |
| Si | ≤ 0.4 % | Silicon supports deoxidation and solid-solution strength and can influence tempering or oxidation response. |
| Mn | 1.1–1.4 % | Manganese contributes to hardenability and sulfur control; its final effect depends on amount and processing. |
| P | ≤ 0.025 % | Phosphorus is normally restricted because higher content can promote embrittlement and reduce toughness. |
| S | ≤ 0.015 % | Sulfur may improve chip control in free-cutting grades but can reduce transverse toughness and weldability. |
| Cr | ≤ 0.4 % | Chromium promotes hardenability and carbide formation and, at sufficient levels, corrosion or oxidation resistance. |
| B | 0.0008–0.005 % | A very small effective boron addition can markedly increase hardenability; process control is critical. |
Source identified in the grade record Sourced with conditions
Engineering behaviour and selection response
Hardness must be reported with delivery/heat-treatment condition; no single grade-wide value applies. Internal comparison index: 55/100.
Engineering analysisToughness has an internal index of 62/100 (moderate). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisImpact resistance has an internal index of 63/100 (moderate). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisBending resistance has an internal index of 75/100 (high). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisWear resistance depends on final hardness, microstructure and wear mode; grade name alone is insufficient for substitution. Internal comparison index: 51/100.
Engineering analysisNot stainless; surface protection is generally required in moist/corrosive service. Internal comparison index: 16/100.
Engineering analysisWeldability has an internal index of 57/100 (moderate). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisMachinability has an internal index of 62/100 (moderate). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisTemperature-dependent behavior varies with condition, exposure time, environment and product form; use sourced values for design. Internal comparison index: 26/100.
Engineering analysisCreep resistance has an internal index of 15/100 (very low). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisFatigue resistance has an internal index of 60/100 (moderate). Actual performance requires a documented product condition, heat treatment and test context.
Engineering analysisNumerical scores are internal comparison indices. They are not standard test results, allowable design stresses or a manufacturer guarantee. Data Method
Hardness and hardenability
Hardness must be reported with delivery/heat-treatment condition; no single grade-wide value applies. Internal screening index: 55/100 (moderate).
moderate
Comparison indexGoverning factors
- Chemistry and section size
- Austenitising and quench severity
- Tempering temperature and time
- Test method and surface preparation
Data limits
Final acceptance requires the current standard, product form, dimensions, delivery condition and heat-specific MTC.
Toughness, impact and fracture behaviour
Impact resistance is indexed at 63/100 and toughness at 62/100. These are not Charpy or Izod energy values; temperature, orientation, geometry and actual microstructure govern component behaviour.
- Microstructure, hardness and grain size influence impact tolerance.
- Sharp radii, notches and surface defects reduce fracture resistance.
- Test temperature, specimen direction and section must be identified.
- For critical parts, accept impact energy only from a documented test of the same condition.
Service temperature, thermal stability and creep
Temperature-dependent behavior varies with condition, exposure time, environment and product form; use sourced values for design. 180–350 °C is a screening range or sourced limit according to its evidence label. Check strength loss, oxidation, creep, exposure time and environment.
Continuous service
180–350 °CEngineering guidanceReview the limit against strength or hardness loss and exposure time.
Intermittent service
Do not assign an intermittent limit without product-specific source data.
Tempering and phase stability
Working and coating temperatures must remain compatible with the tempering condition and required microstructure.
Oxidation and environment
Oxidation or corrosion may become limiting before the strength criterion.
The relative creep index is 15/100 (very low). It is not an allowable creep stress or rupture-life value.
Do not select this grade for long-term static high-temperature loading from the internal index alone.
Wear resistance and surface behaviour
Abrasive wear
Wear resistance depends on final hardness, microstructure and wear mode; grade name alone is insufficient for substitution. The abrasive-wear index is 51/100; final hardness, carbides, microstructure, contact mode and lubrication govern actual resistance.
Comparison indexAdhesive wear
Assess adhesive wear with the counterface material, lubrication, roughness, pressure and temperature.
Engineering analysisSurface improvement
Evaluate surface treatment or coating only after confirming compatibility with chemistry, substrate and process temperature.
Engineering guidanceMechanical and physical properties
The record contains 2 sourced mechanical-property rows; each applies only to its stated condition, dimensions and test temperature.
| Property | Value | Condition | Dimension | Test temperature |
|---|---|---|---|---|
| Tensile strength Rm | ≈ 610 MPa | as rolled strip (thyssenkrupp product) | According to the product data sheet | According to the cited test |
| Mechanical property | ≥ 19 % | as rolled strip (thyssenkrupp product) | According to the product data sheet | According to the cited test |
Physical properties
Heat-treatment stages and process controls
The representative family route is forming or press hardening followed by controlled quenching and tempering where required. Numerical temperatures are shown only when supported by the record.
Annealing / stress relief
Engineering guidanceAssess the supply condition, residual stress, section size and prior machining before selecting time and temperature.
Cooling: Grade- and process-specific coolingPreheating and austenitising
Engineering guidanceSet preheat steps and austenitising parameters from the grade/product data sheet and actual section size.
Cooling: Grade- and process-specific coolingQuenching / controlled cooling
Engineering guidanceChoose the quench medium and cooling severity against hardenability, geometry, distortion and crack risk.
Cooling: Grade- and process-specific coolingTempering / property adjustment
Engineering guidanceSet tempering or ageing to the required hardness, toughness and service-temperature balance.
Cooling: Grade- and process-specific coolingTempering / property adjustment
Engineering guidanceSet tempering or ageing to the required hardness, toughness and service-temperature balance.
Cooling: Grade- and process-specific coolingHardness, toughness, impact, temperature and process charts
Chemistry data retain their evidence label; 0–100 charts are internal indices and stages without temperature are process sequences.
Multi-axis engineering profile
Comparison indexChemical composition
Derived from source dataHardness–toughness balance
Comparison indexToughness, impact and fatigue
Comparison indexWear and surface response
Comparison indexMechanical properties or comparison indices
Sourced with conditionsService temperature
Engineering guidanceHeat treatment
Engineering guidanceRelated-grade similarity
Comparison indexAll comparison indices
Comparison indexPotential failure modes and selection guidance
Potential failure mechanisms
- variable hardenability if boron is not effective or if the heat-treatment and austenite condition are poorly controlled.
- Fatigue initiation from surface defects, section transitions or stress concentration.
- Property loss after unsuitable heat treatment, cooling or finishing.
- Corrosion, oxidation or environmental attack when protection is inadequate.
Selection and design notes
- Match designation, material number, product standard and supply form before purchase.
- Compare the governing failure mechanism with hardness 55, toughness 62, impact 63 and wear 51 indices out of 100.
- Use mechanical values only within their cited condition, dimensions and test temperature.
- Confirm the heat-treatment route and target hardness with the processor before final machining.
- Review the heat number, MTC and required test results before release.
Derived calculations
Calculated from recorded inputs; apply only within the stated formula scope and limitations.
Advantages, limitations and unsuitable applications
Advantages
- useful through-hardening response with relatively economical alloy content.
- A clearly labelled engineering profile supports comparison with related grades.
- Grade identity, chemistry, counterparts and references remain traceable in one dossier.
Limitations and weaknesses
- variable hardenability if boron is not effective or if the heat-treatment and austenite condition are poorly controlled.
- A 0–100 index cannot be converted into design stress, impact energy or creep life.
- Hardness and toughness depend on section, delivery condition and actual processing.
- Do not approve a substitute before checking the product standard and heat-specific MTC.
Cases requiring caution or an alternative material
Industrial applications and processing
Typical applications
- High-strength fasteners and mechanical connections
- Industrial blades, knives and cutting tools
- Automotive powertrain, chassis or formed components
- General engineered and machine components
- wear plates and agricultural parts
- press-hardened automotive components
- heat-treated fasteners and machine parts
- wear-loaded formed components
Manufacture, welding and surface engineering
Weldability has an internal index of 57/100 (moderate). Actual performance requires a documented product condition, heat treatment and test context.
Forming and forging depend on steel family, delivery condition and the grade-specific qualified temperature range.
- Select nitriding, induction hardening or coating against chemistry, substrate hardness and application.
- Keep coating-deposition temperature compatible with the tempering condition and substrate.
- Control hydrogen embrittlement, residual stress and distortion in high-strength components.
Engineering conclusion and selection recommendation
1.5528 / 22MnB5 is worth evaluating when the principal need is useful through-hardening response with relatively economical alloy content. Internal indices of hardness 55/100, toughness 62/100, impact 63/100 and wear 51/100 must be aligned with the real failure mechanism. The leading risk is variable hardenability if boron is not effective or if the heat-treatment and austenite condition are poorly controlled. Final approval requires the current standard, product form, dimensions, delivery condition, heat treatment and heat-specific MTC.
Engineering analysisFrequently asked questions
What is 1.5528 / 22MnB5 steel?
Boron-alloyed heat-treatable steel with high hardenability and widespread use in press-hardening and wear-loaded parts.
What are the main applications of 1.5528 / 22MnB5?
Application contexts include High-strength fasteners and mechanical connections, Industrial blades, knives and cutting tools, Automotive powertrain, chassis or formed components and General engineered and machine components, subject to the product standard and actual condition.
How hard can 1.5528 / 22MnB5 be?
Hardness must be reported with delivery/heat-treatment condition; no single grade-wide value applies. Internal screening index: 55/100 (moderate).
Is 1.5528 / 22MnB5 suitable for impact loading?
Impact resistance is indexed at 63/100 and toughness at 62/100. These are not Charpy or Izod energy values; temperature, orientation, geometry and actual microstructure govern component behaviour.
What is the service-temperature limit of 1.5528 / 22MnB5?
Temperature-dependent behavior varies with condition, exposure time, environment and product form; use sourced values for design. 180–350 °C is a screening range or sourced limit according to its evidence label. Check strength loss, oxidation, creep, exposure time and environment.
Can 1.5528 / 22MnB5 be replaced by a close grade?
Approve substitution only after matching chemistry, specification, product form, condition, heat treatment and MTC.
Engineering steel comparison
Compare this grade with any other dossier. Scores from 0 to 100 are internal screening indices, not laboratory values or allowable design stresses.
Current-grade chemistry
Second-grade chemistry
Current-grade heat treatment
Second-grade heat treatment
Current-grade applications
Limitations
Second-grade applications
Limitations
Select a second grade to update the comparison.
Sources, methodology and evidence
Sources support grade identity, recorded values or the engineering method. General guidance does not replace product-specific certification.
Grade-specific sources
Reference supporting grade identity or recorded values; interpret it within the cited product and condition context. Role: technical.
Reference supporting grade identity or recorded values; interpret it within the cited product and condition context. Role: technical.
Reference supporting grade identity or recorded values; interpret it within the cited product and condition context. Role: official material number register.
Methodology and analysis sources
Reference supporting the calculation method or the limits of the engineering analysis.
Reference supporting the calculation method or the limits of the engineering analysis.
Reference supporting the calculation method or the limits of the engineering analysis.
Reference supporting the calculation method or the limits of the engineering analysis.
Reference supporting the calculation method or the limits of the engineering analysis.
Reference supporting the calculation method or the limits of the engineering analysis.
Dossier reviewed: 2026-08-25 · Evidence status: Sourced numerical data plus engineering analysis
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