Hot rolled hardenable boron steelsHot rolled boron steels have been developed to be hardened, either by heat treatment after workshop processing, or by adirect hot forming & quenching process to get their final properties. Boron steel is a perfect base material for a great varietyof products, parts and components, that need extreme hardness, wear resistance, high strength, toughness and resistanceto mechanical load. These boron steel properties after heat treatment ensure longer lifetime and considerable weightreduction. Good forming­ bending­ welding­ and cutting properties enable the manufacturing of complicated structures,components and parts.

Hot rolled boron steels are delivered in hot rolled (as­rolled) condition as coil, slit coil, cut to length sheet, wide flats, heavyplate and parts.

Boron steels are also available in the form of cold rolled coil, slit coil, cut to length sheet, structural hollow sections,precision tubes and roll­formed profiles.

Applications

• Wear plates

• Grader blades

• Track shoes

• Liner plates

• Screen plates

• Crushers

• Knives

• Saw blades

• Spades

• Hand tools

• Ploughs

• Discs for harrows

• Washers

• Safety parts and components

The information on our web site is accurate to the best of our knowledge and understanding. Although every effort has been made to ensureaccuracy, the company cannot accept any responsibility for any direct or indirect damages resulting from possible errors or incorrect

application of the information of this publication. We reserve the right to make changes.

Copyright © 2015 SSAB or its affiliates. All Rights Reserved.

Document printed on 19.01.2015 www.ruukki.com

Dimensions

Hot rolled boron steels. Dimensions. Cut to length sheet with mill edges

Ruukki grade Thickness mm Width mm Length mm

B 13 2.00 – 12.00 1000 ­ 1800 2000 ­ 13000

B 24 2.00 – 12.00 1000 ­ 1800 2000 ­ 13000

B 27 2.50 – 13.00 1000 ­ 1800 2000 ­ 13000

B 30 2.50 – 12.00 1000 ­ 1800 2000 ­ 13000

B 33 2.50 – 12.00 1000 ­ 1800 2000 ­ 13000

B 36 3.00 – 10.00 1000 ­ 1800 2000 ­ 13000

B 38 3.00 – 10.00 1000 ­ 1800 2000 ­ 13000

B 42 3.00 – 10.00 1000 ­ 1800 2000 ­ 13000

EN 10083­3 grade Thickness mm Width mm Length mm

30MnB5 2.50 – 12.00 1000 ­ 1800 2000 ­ 13000

38MnB5 3.00 – 10.00 1000 ­ 1800 2000 ­ 13000

27MnCrB5­2 2.50 – 13.00 1000 ­ 1800 2000 ­ 13000

33MnCrB5­2 2.50 – 12.00 1000 ­ 1800 2000 ­ 13000

Hot rolled boron steels. Dimensions. Coils with mill edges

Coils 2.00 – 16.00 1000 ­1860

Coils 2.00 – 16.00 870 < 1000*

* by special agreement

Hot rolled boron steels. Dimensions. Slit coils

Slit coils 2.00 – 12.00 75 ­ 910

Hot rolled boron steels. Dimensions. Cut to length sheet from slit coil

Cut to length sheet 2.00 – 12.00 75 ­ 700 900 ­ 16000

The maximum width depends on the strip thickness and the boron steel grade

Hot rolled boron steels. Dimensions. Heavy plates

Ruukki grade Thickness mm Width mm Length mm

B 13 5.00 – 15.00 1901 ­ 3300 2000 ­ 15000

B 24 6.00 – 75.00 1901 ­ 3300 2000 ­ 15000

B 27 5.00 – 80.00 1901 ­ 3300 2000 ­ 15000

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Ruukki grade Thickness mm Width mm Length mm

B 30 8.00 – 65.00 1901 ­ 3300 2000 ­ 15000

EN 10083­3 grade Thickness mm Width mm Length mm

30MnB5 6.00 – 80.00 1901 ­ 3300 2000 ­ 15000

27MnCrB5­2 5.00 – 80.00 1901 ­ 3300 2000 ­ 15000

The minimum/maximum width and the maximum length depend on the plate thickness.

Hot rolled boron steels. Dimensions. Wide flats cut from plate

Wide flats 10.00 – 60.00 150 ­ 800 4500 ­ 19500

Tolerances

Dimensional and shape tolerances:

• Hot rolled coil, slit coil and cut to length sheets: EN 10051

• Heavy plates: EN 10029; thickness according to Class A.

Surface quality

EN 10163­2 Class A3.

Surface condition

Coils, slit coils and cut to length sheets are available in as­rolled, pickled­ and pickled & oiled condition.

Heavy plates are available in as­rolled, shot blasted and shot blasted / shop primed condition.

Properties

Mechanical properties

Hot rolled boron steels. Mechanical properties. Approximative values

Ruukki Grades Condition Yield strength MPa Tensile strength MPa ElongationA %

HardnessHB / HBW

B 13 Hot rolled

Water quenched

400

900

570

1200

25

10

160 HB

370 HB

B 24 Hot rolled

Water quenched

400

1100

600

1500

25

8

160 HB

430 HB

B 27 Hot rolled

Water quenched

420

1200

620

1600

22

6

170 HB

470 HBW

B 30 Hot rolled

Water quenched

420

1250

620

1850

20

6

190 HB

530 HBW

B 33 Hot rolled

Water quenched

420

1300

620

1900

22

6

190 HB

550 HBW

B 36 Hot rolled

Water quenched

420

1350

620

1950

19­

6

190 HB

570 HBW

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Ruukki Grades Condition Yield strength MPa Tensile strength MPa ElongationA %

HardnessHB / HBW

B 38 Hot rolled

Water quenched

430

1400

630

2000

19

6

190 HB

600 HBW

B 42 Hot rolled

Water quenched

440

1500

660

2200

18

5

190 HB

630 HBW

EN 10083­3 Grades Condition Yield strength MPa Tensile strength MPa ElongationA %

HardnessHB / HBW

30MnB5 Hot rolled

Water quenched

420

1250

620

1850

20

6

190 HB

530 HBW

38MnB5 Hot rolled

Water quenched

430

1400

630

2000

19

6

190 HB

600 HBW

27MnCrB5­2 Hot rolled

Water quenched

420

1200

620

1600

22

6

170 HB

470 HBW

33MnCrB5­2 Hot rolled

Water quenched

420

1300

620

1900

20­

6

190 HB

550 HBW

Materials testing

A test certificate according to EN 10204/2.2 (chemical composition) is part of the delivery.

A test certificate according to EN 10204/3.1 can be provided by special agreement only.

Chemical composition and carbon equivalent

Carbon equivalent :

CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15

Hot rolled boron steels. Chemical composition. Content % (ladle analysis) and carbon equivalent (CEV). The steelsare grain­refined

Ruukki grade Cmax

Simax

Mnmax

CrMax

Bmin­max

CEV typical

B 13 0.17 0.40 1.30 1.30 0.0008­0.0050 0.46

B 24 0.26 0.40 1.50 0.50 0.0008­0.0050 0.51

B 27 0,32 0.40 1.50 0.60 0.0008­0.0050 0.54

B 30 0.34 0.40 1.50 0.50 0.0008­0.0050 0,59

B 33 0.36 0,40 1.50 0.60 0.0008­0.0050 0.60

B 36 0.40 0,40 1.50 0.60 0.0008­0.0050 0.65

B 38 0.43 0.40 1.40 0.40 0.0008­0.0050 0.65

B 42 0.45 0.40 1.40 0.50 0.0008­0.0050 0.70

P max = 0.020% and S max = 0.015%.

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EN 10083­3 grade Cmin­max

Simax

Mnmin­max

Crmin­max

Bmin­max

CEV1) typical

30MnB5 0.27­0.33 0.40 1.15­1.45 ­ 0.0008­0.0050 0.56

38MnB5 0.36­0.42 0.40 1.15­1.45 ­ 0.0008­0.0050 0.60

27MnCrB5­2 0.24­0.30 0.40 1.10­1.40 0.30­0.60 0.0008­0.0050 0.55

33MnCrB5­2 0.30­0.36 0.40 1.20­1.50 0.30­0.60 0.0008­0.0050 0.62

P max = 0.025% and S max = 0.035%.

1) Ruukki values, not given in EN 10083­3.

Prefabrication services

Ruukki offers a wide range of prefabrication services that enable you to speed­up your production process, save on storagecost and reduce waste material.

• Wide flats cut from heavy plate or cut to length sheet

• Precision­ and shape cut parts and components from heavy plate and sheet

• Beveled heavy plate and sheet

• Bent plate­ and sheet

• 3D Laser cut structural hollow sections and roll­formed profiles.

Processing instructions

In the as­rolled condition, boron steels can be processed in nearly the same way as structural steels of the same strengthlevel. After hardening, boron steels can be processed similarly to wear­resistant steels. Sheets and plates that are takenfrom cold storage to workshop processing, such as cutting, bending and welding, should be warmed­up to roomtemperature (+20°C) beforehand.

Bending

Hot rolled boron steels in as­rolled condition are more formable and allow smaller bending radii (see table below) thanboron steels in hardened condition. Hardened boron steels require higher bending force and will show more spring­backeffect than boron steels in hot rolled condition.

The minimum bend radius recommendations are shown in the following table.

Hot rolled boron steels. Cut to length sheet and heavy plates, as­rolled condition.

Minimum permissible bend radius, bend angle 90°, all bending directions

Cut lengths Thickness ≤ 12mm

Ruukki grade Minimum internal bending radius mm

B 13 2 x t

B 24 2 x t

B 27 2 x t

B 30 3 x t

B 33 3 x t

B 36 5 x t

B 38 5 x t

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Cut lengths Thickness ≤ 12mm

B 42 5 x t

Heavy plates Thickness ≤ 16mm

Ruukki grade Minimum internal bending radius mm

B 13 3 x t

B 24 4 x t

B 27 4 x t

B 30 5 x t

It is recommended to contact Ruukki's Technical Customer Service prior to cold forming of boron steel plates in as­rolledcondition thicker than 16 mm. Generally, it is recommended to pre­heat plates thicker than 16 mm before forming.

NOTE: Carefully consider the following when cold forming:

• Bending tools should be in excellent shape

• Sufficient lubrication

• Plate/sheet surface must be free of defects

• Cut edges must be free of burrs

• Respect the recommended minimum bending radius.

Welding

Hot rolled boron steels can be welded both in as rolled­ or in hardened condition, using common (semi)automated­ ormanual welding processes. The best results can be obtained by using low hydrogen welding methods­ and consumables(weld metal hydrogen content HD ≤ 5 ml/100 g). Preferably use MAG welding and a welding sequence that is designed tominimize residual stresses.

How to prevent cold cracking

Hot rolled boron steels, especially in hardened condition, can be sensitive to cold cracking in the heat affected zone of aweld. Cold cracking can be avoided by taking following measures and precautions:

• Clean the weld joint area to shiny steel, removing potential sources of hydrogen: rust, scale, moisture, grease etc.

• Use a low hydrogen welding process

• Use low strength ferritic­ or austenitic consumables

• Make sure that the steel is at room temperature; pre­heat if necessary.

• Minimum heat input in welding

More information about welding of high strength steels can be found in EN 1011­2 (Welding. Recommendations for weldingof metallic materials. Part 2: Arc welding of ferritic steels), or ask your contact person or our technical customer service.

Pre­heating

An effective way of avoiding cold cracks, both in the parent steel and in the weld metal, is pre­heating.

The sensitivity to cold cracking can be estimated based on the carbon equivalent value that you can find in the material testcertificate. In the following table, you will find recommendations regarding pre­heating and working temperature. Pre­heating is especially important when welding with low heat input, such as in tack welding or welding root passes.

Working temperature (°C) for welding (EN 1011­2). Hot rolled boron steels in the as­rolled condition. Weld metalhydrogen content HD ≤ 5 ml/100 g

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When welding boron steel grades B 33, B 38 and B 42 cut to length sheet with a thickness > 10 mm, we recommend pre­heating up to +50 ­ 100°C.

Welding consumables

Welding with low­alloyed consumables usually leads to a relatively low strength in the heat affected zone.

This offers considerable advantages: the weld metal will have higher toughness, better forming properties and lowerresidual stresses compared to welding with higher­alloyed consumables.

If the welded joints are positioned in low stress areas and the wear resistance of the weld is not critical, low­alloyedconsumables are recommended.

Hot rolled boron steels. Low­alloy ferritic welding consumables. Yield strength ˂~500 MPa

Welding process Consumables

MAG Solid wire OK Autrod 12.51, OK Aristorod 12.63, LNM 26, Böhler EMK 6, Carbofil 1

MAG Flux cored OK Tubrod 15.14, OK Tubrod 15.17, Union RV 71, Outershield 71 E­H

MAG Metal cored OK Tubrod 14.11, OK Tubrod 14.12, OK Tubrod 14.05, Union MV 70, Fluxofil M8

MMA Electrode OK 48.00, OK 55.00, P48S, Conarc 48, Supercito, Böhler FOX EV 50

SAW wire + flux OK 12.22+OK Flux 10.71, Union S 2 + UV 400, OE­S2 + OP 122

The selection above is not exclusive and should not be interpreted as disqualification of other corresponding consumablesin any way. Corresponding consumables from other suppliers/manufacturers are equally recommended. The validity of anyrecommendation should be verified with the manufacturer before welding.

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High­alloyed (high strength) ferritic consumables can be used when a more hardened weld metal is required or when wearresistance is required on the welded joint. The yield strength level of these consumables is typically 700 MPa. Usually, theuse of these consumables can be limited to the surface layers. Please note that it is recommended not to use high­alloyedconsumables prior to quenching.

Welding after hardening

Generally, welding of boron steels after hardening can be compared to welding of wear­resistant steels.

After welding, there will be a narrow zone, softer than the base material, in the heat­affected zone. The width of this softerzone depends on the heat input.

The best way to limit the softening effect is to use moderate heat input. Thicker plates are more robust to thesoftening effect than thin plates.

The softer zone does usually not affect the durability of the welded structure. The working temperature or the inter­passtemperature should not be higher than +200°C.

Higher temperatures may cause reduced hardness in the welded joint. The risk for cold cracks can be minimized by usingaustenitic low strength consumables.

Download information about welding hot rolled steel

Thermal cutting

The most commonly used thermal cutting methods are flame cutting, plasma cutting and laser cutting. Special care must betaken when cutting hardened boron steel or thick boron steel plates in as­rolled condition. Hardening cracks can be avoidedby means of pre­heating. Practical experience has shown that even moderate pre­heating is beneficial. The following tableshows the working temperature recommendations for B 24, B 27 and B 30 steel grades.

Working temperatures for flame cutting. Hot rolled boron steels in the as­rolled condition.

RuukkiGrade

Thickness Working temperature

B 24 10 – 30mm +50 – +75°C

B 24 (30) – 60mm +75 – +125°C

B 27 10 – 75mm +125 – +175°C

B 30 10 – 65mm +125 – +200°C

When flame cutting boron steel grades B 33, B 38 and B 42 cut to length sheet with a thickness > 10 mm, we recommend pre­heating up to +50 ­ 100°C.

By choosing a lower cutting speed, selecting the right cutting nozzles and other equipment, pre­heating may not always benecessary. When flame cutting hardened boron steel plates, the hardness tends to decrease in areas where thetemperature exceeds +200°C. Small components and thin plate/sheet are more sensitive to decreased hardness whenflame cutting.

Mechanical cutting

Hot rolled boron steels in the as­rolled condition can be mechanically cut in the same way as structural steels of the samestrength level. Mechanical cutting of hardened boron steels is challenging, as the hardness of the steel approaches that ofthe cutting blades. B 13 and B 24 can be mechanically cut using heavy, robust machines. Mechanical cutting of higher­alloyed boron steel grades B 27 – B 42 is technically possible for plate/sheet with thickness < 10 mm, but requires goodenough equipment and expertise.

Machining

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Hot rolled boron steels in the as­rolled condition can be machined in the same way as structural steels of the same strengthlevel. Robust machinery and hard metal bits are recommended for machining hardened boron steels. Hardened boron steelplates can be drilled with high­speed steel bits if the bit geometry and cutting fluid are correctly chosen.

Further information on processing in technical datasheets and .

Occupational safety

Special care must be taken in all stages of processing boron steels in the as­rolled condition, as boron steels have strongwork hardening properties. It is important to follow the recommendations as given by the steel supplier. Bending equipmentoperators should take appropriate precautions to protect themselves. Unauthorized persons should not be allowed to be inthe bending equipment area.

The processing instructions of the steel supplier and the safety instructions of the workshop must be obeyed. Newemployees must receive appropriate training before they are allowed to process boron steels.

More information can be found on the links below

Download Ruukki’s General Condition of Sale

Order & delivery

Delivery condition

The delivery condition for hardenable boron steel is hot­rolled.

Inspection document

The inspection document states the chemical composition in compliance with EN 10204.

Ruukki provides boron steel deliveries with the so­called Analysis certificate.

Alternatively, on the customer’s request, we either provide the Test report 2.2 or the Inspection certificate 3.1., inaccordance with EN 10204.

General delivery information for hot­rolled steels

General delivery information can be found from documents Markings and packing, Ultra­sonic testing and General terms ofsale.

The content of this document has been created from web page last updated 9 Jan 2015Our sales and technical support are happy to give you more information. Visit www.ruukki.com/contact­us.

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