Structural Engineering Steel

SIQUAL Structural Steel

Name: SIQUAL Structural Steel
Brand: SIJ Metal Ravne

SIJ brand for structural and high-quality engineering steels

SIQUAL Structural Steel from SIJ Metal Ravne covers case-hardening, quenching and tempering, nitriding, spring and pressure vessel steels for components that need strength, ductility, toughness and elongation.

Manufactured bySIJ Metal Ravne · HTS Group

Rows of machined steel rings and sleeves on an inspection station — Machined steel rings and sleeves.

> 60 HRCCase-hardened surface

Ø1,050 mmForged and turned bars up to

20,000 kgOpen-die forgings up to

6 conditionsAs rolled to quenched and tempered

Overview

Structural steels for strength and toughness

SIQUAL structural steels are used where components require a combination of strength, ductility, toughness, elongation and consistent mechanical performance. Depending on alloying and application, they are supplied as non-alloyed structural, low-alloyed, alloyed, pressure vessel, case-hardening, quenching and tempering, nitriding, spring and bearing steels.

They are used in aviation structures, offshore installations, pressure vessels, mechanical engineering, construction and automotive applications.

SIJ Metal Ravne produces the steel by recycling scrap in an electric arc furnace, casting it into ingots, then rolling or forging it into long products, with ESR remelting, heat treatment and machining options. HTS Group / Ravne Steel Center is the official distributor and service center.

Steel Families

Main SIQUAL application groups

Hard surface, tough core

Case-hardening steels

Carbon-enriched surface, then quenched and tempered; surface hardness above 60 HRC after proper carburizing, quenching and tempering.

SIQUAL 7131 / 1.7131 / 16MnCr5
SIQUAL 7147 / 1.7147 / 20MnCr5
SIQUAL 6566 / 1.6566 / 17NiCrMo6-4
SIQUAL 6587 / 1.6587 / 18CrNiMo7-6
SIQUAL 7321 / 1.7321 / 20MoCr4
SIQUAL S140 / AISI 3310

Strength with ductility

Steels for quenching and tempering

Final balance of strength, hardness, toughness and plasticity; supplied annealed or quenched and tempered.

SIQUAL 7225 (Q+T): 900–1100 N/mm²

SIQUAL 7225 / 1.7225 / 42CrMo4 / AISI 4142
SIQUAL 6582 / 1.6582 / 34CrNiMo6
SIQUAL 6580 / 1.6580 / 30CrNiMo8
SIQUAL 6510 / 1.6510 / 39NiCrMo3
SIQUAL 7218 / 1.7218 / 25CrMo4
SIQUAL 7220 / 1.7220 / 34CrMo4

Very low distortion

Nitriding steels

High surface hardness and wear resistance with almost no shape or dimensional change in final heat treatment; delivered annealed or quenched and tempered.

SIQUAL 8509 / 1.8509 / 41CrAlMo7-10
SIQUAL 8515 / 1.8515 / 31CrMo12
SIQUAL 8519 / 1.8519 / 31CrMoV9
SIQUAL 8550 / 1.8550 / 34CrAlNi7-10

High yield strength

Spring steels

High strength and yield strength after final heat treatment; high cleanliness supports long service life.

SIQUAL 1231 / 1.1231 / C67S
SIQUAL 1248 / 1.1248 / C75S
SIQUAL 1260 / 1.1260 / 66Mn4
SIQUAL 5024 / 1.5024 / 46Si7

Above or below atmospheric pressure

Pressure vessel steels

For containers, boilers, pipes and turbine housings; alloying adjusted to the application.

Molybdenum for elevated-temperature resistance.
Nickel for low-temperature properties.
Chromium for corrosion resistance.

Product Range

Product forms and sizes

Round bars

Rolled: Ø15–105 mm, 3,000–6,000 mm
Peeled / polished: Ø15–80 mm, 2,500–6,000 mm
Ground / polished: Ø6–80 mm, 2,000–4,000 mm
Forged and peeled: Ø105–205 mm, 2,000–6,000 mm
Forged and turned: Ø206–1,050 mm, 2,000–6,000 mm
Cold-drawn: Ø2–120 mm

Flats and forgings

Rolled flats: 40–150 × 7–65 mm
Rolled flats, DIN 59200: 155–255 × 15–65 mm
Wide flats: 250–505 × 26–90 mm
Forged squares: up to 850 mm
Forged flats: up to 1,600 × 450 mm
Open-die forgings: Ø1,000 mm, 10,000 mm, 20,000 kg

Delivery conditions

As rolled.
Normalized rolled.
Normalized.
Annealed.
Normalized and tempered.
Quenched and tempered.

Electric arc furnace and ladle area in the SIJ steel plant with glowing molten steel

Production route

SIJ Metal Ravne melts recycled scrap in an electric arc furnace and casts it into ingots before rolling or forging.

Applications

Where SIQUAL is used

Shafts, gears and axles

Machine and automotive parts that need high strength with good toughness.

Rings and sleeves

Mechanical engineering parts made from case-hardening and quenched and tempered grades.

Case-hardened and nitrided parts

Parts that need a hard, wear-resistant surface and low distortion.

Springs

Spring steel grades for parts that need high yield strength.

Pressure vessels and boilers

Pressure vessel grades for pipes, boilers and turbine housings.

Offshore and aviation structures

Structural components for demanding industrial environments.

Automotive componentsEngineering componentsBoltsFastenersMandrelsRollsCutting and forming componentsQuenched and tempered partsHydraulic systemsPneumatic systemsPipes for high or low temperatureHeavy-duty industrial components

Features

Properties and steel types

Mechanical properties

High yield and tensile strength.
Good elongation, ductility and toughness.
Good fatigue resistance depending on grade and heat treatment.

Steel types

Low-alloyed and alloyed steels.
Case-hardening, quenching and tempering, and nitriding steels.
Spring, pressure vessel and bearing steels.

Product forms

Plates, hot-rolled and cold-rolled sheets.
Round bars, flat sections and forgings.
Coils and strips.

Benefits

Why SIQUAL for components

Strength with toughness. High strength with good toughness and ductility for high-load and cyclic-load parts.

Hard surface, tough core. Case-hardening grades give a hard surface over a tough core.

Low distortion. Nitriding grades give high surface hardness with very low distortion.

Controlled properties. Quenching and tempering grades give controlled final mechanical properties.

Wide size range. The dimensional range covers small, medium and large components.

Metallurgical control. The SIJ production route gives strong metallurgical control.

Need support with this structural steel?

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