Steel structures

KGHM ZANAM S.A. has been a recognised manufacturer of large-size welded steel structures for many years. Steel structures manufactured by us include hoisting equipment (skips), cages, and shaft hangers. KGHM ZANAM is also capable of manufacturing other steel structures based on provided technical documentation. The experience of our team, our technological potential as well as approvals and certificates held by us ensure high quality of manufactured structures. Our products are covered by servicing agreements.

Manufacture of steel structures – technology

The range of technological operations carried out by us can be divided into following phases:

• pre-treatments

• folding and bonding

• machining

• thermal treatment

• machine and equipment assembly

• corrosion protection

1. Pre-treatment

1.1. Cleaning

Cleaning of 2,500 × 6,000 mm and 2,500 × 12,000 mm sheets on pass-through casting cleaning plants. Cleaning of 12 × 5 × 5 [m] structures in a shot blast cleaner.
Surface cleanliness of metal sheets obtained following shot blasting is compliant with PN-ISO 8501-1: Sa21.

1.2. Cutting

Manufacturing of our structures involves cutting of bars, pipes, sections and closed profiles on automatic belt cutting-off machines. The maximum diameter of the cut at right angle is Ø330 mm and the maximum dimension of the cut profile is 330 × 510 mm.

Cutting profile shapes and sheet metal with a thickness of up to 25 mm on guillotine shears

Gas cutting of carbon steel sheets with a thickness of up to 200 mm and dimensions of 2,500 × 6,000 mm on CNC thermal cutters. Plasma cutting of alloy steel and non-ferrous metal sheets with a thickness of up to 15 mm and dimensions of 4,000 mm × 6,000 mm on a CNC thermal cutter.

Semi-automatic gas cutting of metal sheets with a thickness of up to 100 mm, chamfering on straight sections of metal sheets

1.3. Plastic forming

Bending on a cornice brake with a nominal pressure between 250 and 600 Mg.

Straightening of work pieces and sheet metal is done using eccentric and hydraulic presses with pressures between 25 and 160 Mg and between 25 and 250 Mg, respectively.

The company also offers roller circle bending for metal sheets with a thickness of up to 30 mm and width of up to 3,000 mm.

2. Welding of steel structures

2.1. Welding methods

Utilised arc welding methods:

• manual metal arc welding (MMA)

• semi-automatic metal inert gas/metal active gas welding (MIG/MAG)

• tungsten inert gas welding (TIG)

• submerged arc welding

The following materials can be welded:

• carbon steels

• low-alloy steels with increased strength and wear resistance

• high-alloy, stainless and acid-resistant steels

Welding stress relieving by:

• thermal treatment of structures

• vibration annealing

Welded structures are manufactured in accordance with the following certificates and standards:

• Certificate of Qualification of Group I Large Plants, as per PN-M-69009 (confirming class 1, 2 and 3 for manufacture of structures, as per PN-M-69008)

• Certificate as per DIN EN IS0 3834-2 (confirming the welding quality system in full scope)

• Certificate as per EN 1090-2 (confirming manufacture of steel civil engineering structures up to class EXC3)

• Certificate as per EN 1090-1 (confirming the approval of the FPC: FACTORY PRODUCTION CONTROL)

2.2. Weld monitoring, test methods

Non-destructive tests:

• visual (VT)

• penetration (PT)

• magnetic-powder (MT)

• ultrasonic (UT)

• radiographic (RT)

Destructive tests of sample or inspection welds (mechanical property tests):

• static weld tension

• weld bending

• weld impact strength

• weld breaking

• hardness

Checking of:

• steel chemical composition

• steel weldability

2.3. Thermal treatment

• standardisation

• stress relief annealing

We have at our disposal modern welding equipment used in manufacturing of steel structures, e.g:

• “FRONIUS” TPS 4000 and TPS 5000 semi-automatic welding machines

• “ESAB” column-and-boom manipulator for submerged arc welding with longitudinal and circumferential welds on tanks and pipes

• automatic unit for hole regeneration (overlay welding) Ø 30 /mm/ to Ø 600 /mm/, max. length 500 /mm/

3. Machining of structures

The structures are machined on vertical and universal milling machines, both conventional and CNC, as well as planner milling machines. Workbench dimensions are 1,250 × 4,000 mm. Maximum machining width is 1,250 mm. Maximum machining height is 1,250 mm.

Machining on conventional drill and milling machines with rotary workbench and spindle diameter of up to Ø 160 mm, with electronic position reading. Maximum boring diameter is Ø 1,000 mm.

Machining on plate drill and milling machines (two plate drill and milling machines with spindles directed towards each other) with spindle diameters of Ø 115 and with electronic position reading, and on CNC models with spindle diameters of Ø 130. Maximum boring diameter is 1,000 mm.

4. Corrosion protection

4.1. Painting

Painting of machines, welded structures and work pieces in chamber dryers with dimensions of
6 × 16 × 5 m and 5 × 6 × 5 m. Hydrodynamic and pneumatic coating with one-component and two-component paints. Utilised paint sets are either three-coat paints (primer, intermediate coat and topcoat) or customer-defined. Total thickness of paint coating on steel structures is 140-160 µm.

4.2. ZINGA galvanising

This solution is used to provide an independent protective coating for various types of steel structures, e.g. bridge structures, road safety barriers, containers or skips, mast towers, silos, heavy equipment chassis, construction machinery, freight wagons, culverts and many others.