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Material data sheet

Steel grade

Last revised: Wed, 01 Mar 2023 09:17:17 GMT

General Information

Ovako 824 is a through hardening bearing steels intended for rolling contact and other high fatigued applications. In the hardened condition the high hardness, high strength and high cleanliness provides the steel with the right properties to withstand high cycle, high stress fatigue. Ovako 824 is mainly used for small and medium sized bearing components. It is also regularly used for other machine components that require high tensile strength and high hardness. The hardenability approximately corresponds to a ring with maximum 20 mm wall thickness. It is suitable for both martensitic and bainitic hardening. Ovako 824 comes in two variants. One Bearing Quality (BQ) variant that fulfills tough Ovako internal quality demands and consequently also the ISO 683-17 demands. One Isotropic Quality (IQ) with higher demands regarding micro inclusion cleanliness and improved isotropic properties. Additionally this variant has a slightly reduced carbon content to reduce the carbide segregation tendency. The IQ variant is especially suited for applications subjected to a complex loading mode.

824B - Bearing quality (BQ) variant 

824P - Bearing quality (BQ) variant with low sulphur content

824Q - Isotropic quality (IQ) variant

For additional Heat Treatment Data, please visit the Heat Treatment Guide.

 

BQ-Steel®
(Bearing Quality) is a bearing quality clean steel optimized for fatigue strength by a strict control of steel cleanliness. BQ-steel is also ideal for new design solutions in a wide array of demanding applications outside the bearing industry that require longer performance and higher loads. The BQ-steel offer is the result of the Ovako clean steel program. Purity of production means that the material has significantly smaller inclusions compared to conventional steel and, as a result, the fatigue strength of the steel is increased dramatically. Use of the material allows components to be manufactured in smaller sizes. The BQ-steel  has for decades been the problem-solver

IQ-Steel®
(Isotropic Quality) is an isotropic quality ultra clean steel. IQ-Steel is optimized for fatigue strength by a strict control of steel cleanliness. IQ-Steel, a further development of BQ-Steel, is an isotropic and ultra clean steel with properties that match re-melted steels. Based on thousands of examinations by Ovako into the effects of defects on fatigue performance, the metallurgy of IQ-Steel is purer and far more consistent than conventional grades, and designed specifically to perform well in multi axial loading. This enables the manufacturing of lighter, slimmed down components like gears, bearings and other critical parts. The steels are helping our customers to achieve new design solutions and implement higher standards of finished product performance. Key to these practical advantages are Ovako’s own unique, clean and consistent modern steelmaking processes that remove harmful inclusions and impurities from within the steel. IQ-Steels contain smaller and more fragmented inclusions and can handle much higher mechanical forces in all directions than conventional steels. IQ-Steels are newer, but already now well established in high pressure automotive applications. Modern diesel engines, with high and cyclic injection pressures, have proven to be an ideal application. Transmission components are another emerging area of strong interest.

IQ-Steel® 

IQ-Steel® is an isotropic quality ultra clean steel optimized for high fatigue strength under multi axial loading.

BQ-Steel® 

BQ-steel® is a bearing quality clean steel optimized for fatigue strength and is also ideal for new design solutions outside the bearing industry.

Similar designations

100CD7, A485-3

Mechanical properties are valid for all steel grade variants

CCT

Steel cleanliness

Micro inclusions -  Ovako 824B + 824P   Macro inclusions -  824B + 824P
Applied standard ASTM E45 Applied standard

ISO 3763

(Blue fracture)

Sampling ASTM A295 Sampling Statistical testing on billets.

Maximum

average limits

A B C D Limits < 2,5 mm/dm2
Th He Th He Th He Th He
2,0 1,5 0,8 0,1 0 0 0,5 0,3
 
Micro inclusions - IQ   Macro inclusions - IQ
Applied standard DIN 50602  K1 Applied standard

ISO 3763

(Blue fracture)

10 M Hz UST

(Ovako internal procedure)

Sampling Six random samples from final product dimension Sampling Statistical testing on billets
Limits

The limit is dimension dependent. The average rating of six samples should not exceed the

limits given in the graph

Limits < 1 mm/dm2

< 5 defects/dm3 

> 0,2 mm FBH 

IQ

Other properties (typical values)

Youngs module (GPa)Poisson´s ratio (-)Shear module (GPa)Density (kg/m3)
210 0.3 80 7800
 Average CTE 20-300°C (µm/m°K) Specific heat capacity 50/100°C (J/kg°K) Thermal conductivity Ambient temperature (W/m°K) Electrical resistivityAmbient temperature (µΩm)
 12  460 - 480  40 - 45  0.20 - 0.25

Contact us

Would you like to know more about our offers? Don´t hesitate to contact us:

Via e-mail: info@ovako.com 

Via telephone: +46 8 622 1300

For more detailed information please visit http://www.ovako.com/en/Contact-Ovako/

  

 

Disclaimer

The information in this document is for illustrative purposes only. The data and examples are only general recommendations and not a warranty or a guarantee. The suitability of a product for a specific application can be confirmed only by Ovako once given the actual conditions.The purchaser of an Ovako product has the responsibility to ascertain and control the applicability of the products before using them. Continuous development may necessitate changes in technical data without notice. This document is only valid for Ovako material. Other material, covering the same international specifications, does not necessarily comply with the properties presented in this document.