Quenched and Tempered Steel

Quenched and Tempered Steel Plate from Brown McFarlane

Brown McFarlane offers one of the largest ranges of high strength quenched and tempered structural steel plate in Europe.

It is not uncommon in our industry to find the same type of steel plate given different names by different engineers. Plates of this type are variously described as:

• High Strength Quenched and Tempered Steel Plate
• High Yield Quenched and Tempered Steel Plate
• High Strength Structural Steel Plate,
• High Yield Structural Steel Plate
• High Strength Low Alloy Steel Plate
• HSLA

What is the Quenching and Tempering Process?

In order to achieve optimal ductility, strength and hardness, steel goes through a two-step heat treatment process called quenching and tempering.

This involves the material being austenitized to around 900℃ and then rapidly cooled by quenching. The steel plate is water-quenched in a separate unit, usually being clamped down to avoid warping.

The resulting steel is brittle and stressed, requiring it to go through the second stage of the heat treatment process - tempering.

Tempering involves reheating the quenched steel plate to a temperature just below critical, then allowing it to cool at a predetermined rate. This restores some of the ductility of the metal.

What are the Advantages of Quenched and Tempered Steel Plate?

A variety of steel specifications are available including those with a minimum yield strength of 690 MPa and with a minimum yield strength of 890 MPa. The stock encompasses a range of sophisticated high-strength low-alloy steel plates from leading Western European producers and is supplied in plate thicknesses from 3mm up to 300mm.

Quenched and tempered structural steel plate has been developed for industrial uses where a combination of strength and outstanding toughness are necessary. These include mining and quarrying, material handling, construction and earthmoving, and offshore fabrication.

Quenched and tempered steel has the considerable advantage of providing high strength while offering weight reductions - this improves the efficiency of plant and equipment. It is used in the manufacture of cranes, forklift trucks, bridges, mooring equipment, vehicle chassis, to name but a few applications.

Quenched and Tempered Steel Specifications and Grades

Specifications and grades available from Brown McFarlane's stock include:

EN 10025 S690QL, EN 10025 S890QL, EN 10025 S960QL.

Quend 700 from NLMK Clabecq.

RQT® 701, RQT® 901 (proprietary brands manufactured by Tata Steel) were previously stocked however are no longer manufactured. You can read about RQT 701 and its alternatives here.

Fabrication of High Strength Quenched and Tempered Steel Plate.

High strength quenched and tempered steel plate can be easily welded and fabricated. Its high yield strength and tensile strength compared with mild steel means that it should be treated with some caution.

We have provided information which is intended as a basic guide to various fabrication methods. If you require more detailed advice on welding, machining, or forming then please contact any one of our offices.