Hard, wear-resistant rolls for finishing stands of bar and rebar mills.
As the bar moves through the mill, thermal wear becomes less important and mechanical wear (abrasion) becomes the main problem. Harder grades with more carbides and alloy content are preferred.
Finishing rolls must keep the groove shape, give a good surface on the product and allow long campaigns. We supply finishing rolls for rounds, flats and rebar, including notched rolls for rebar marking, slitting rolls for multi-strand rolling and composite rolls.
- Finishing stands for rounds, flats and rebar
- Notched rolls for rebar rib marking
- Slitting rolls for 2, 3 and 4-strand slitting
- Composite rolls for pre-finishing and finishing
Available grades
Material grades
SG Pearlitic
SG Pearlitic iron has nodular (spheroidal) graphite and carbides in a pearlitic matrix. Its properties are close to Alloy Indefinite Chill, but the graphite is in spheroidal form instead of flakes, so SG Pearlitic rolls have higher strength.
It is suitable for both roughing and finishing stands and covers a wide range of applications.
Variants: SGP alloyed with chromium gives deep carbide penetration, a lower hardness drop and good wear resistance — recommended for rolls with deep grooves. SGP alloyed with molybdenum and nickel, with high-temperature heat treatment, gives excellent resistance to fire cracks, high strength and better impact resistance than flake graphite iron.
Production type
Chemical composition (%)
| C | Si | Mn | Ni | Cr | Mo |
|---|---|---|---|---|---|
| 3.00–3.40 | 1.00–2.00 | 0.30–0.80 | 1.00–2.60 | 0.10–0.90 | 0.30–0.80 |
Properties
SG Acicular
SG Acicular is alloyed with nickel, manganese and chromium and has a bainitic–acicular–martensitic matrix. It has higher tensile strength, higher hardness and better wear resistance than SG Pearlitic.
Semi-continuous carbides keep the wear resistance, while the grade keeps high strength and good resistance to fire cracks. A full heat treatment cycle makes sure the matrix is acicular.
Chromium-alloyed SG Acicular grades give deep carbide penetration, a lower hardness drop and better wear resistance — recommended for rolls with deep grooves.
Production type
Chemical composition (%)
| C | Si | Mn | Ni | Cr | Mo |
|---|---|---|---|---|---|
| 3.00–3.50 | 1.00–2.20 | 0.30–1.00 | 2.50–5.00 | 0.30–1.50 | 0.30–1.00 |
Properties
Alloy Indefinite Chill
Alloy Indefinite Chill (AIC) rolls are cast iron with fine interdendritic graphite spread evenly through the barrel. The size, shape and distribution of the graphite, and the carbide content, are controlled by the chilling effect and the alloy content.
Alloys such as manganese, nickel, chromium and molybdenum change the matrix from pearlitic, through bainitic, to martensitic. This improves strength, hardness in depth and wear resistance. The fine graphite improves thermal conductivity, which reduces fire cracks, and its damping capacity helps to reduce spalling when large reductions are needed.
The gradual change of hardness makes AIC ideal for deep grooves. It is used in roughing and finishing stands for bars and sections, and in roughing and intermediate stands of wire rod mills. Martensitic AIC with high hardness is suitable for finishing stands of wire rod mills.
Production type
Chemical composition (%)
| C | Si | Mn | Ni | Cr | Mo |
|---|---|---|---|---|---|
| 3.00–3.50 | 0.60–1.20 | 0.50–1.20 | 1.00–5.00 | 0.70–2.00 | 0.10–0.50 |
Properties
Rápido HSS
Rápido HSS (high speed steel) rolls have high hardness and keep good wear resistance at high temperatures. The grade is made only by horizontal centrifugal casting, with a core of spheroidal graphite pearlitic iron.
The composition and heat treatment give the HSS working layer a hardness of 70–85 Shore C (selected for each stand position), uniform through the full working layer. Complex carbides of vanadium, tungsten, niobium and molybdenum in a martensitic matrix give uniform wear and very high wear resistance.
HSS is used in finishing stands for longer campaigns and a better surface finish on the product.
Production type
Chemical composition (%)
| C | Si | Mn | Cr | Mo | V | Ni |
|---|---|---|---|---|---|---|
| 1.6–2.0 | 0.3–1.0 | 0.3–1.0 | 4.0–8.0 | 4.0–6.0 | 4.0–6.0 | 0.5–1.5 |
Properties
Rápido Toolsteel
Mills are looking for alternatives to tungsten carbide, and this has led to iron-matrix materials with a high carbide content. Rápido Toolsteel is a sintered material that works at both the highest and the lowest rolling speeds.
Typical uses: pinch, looping and transport rolls, KOCKS reducing and sizing blocks, and composite rolls in pre-finishing stands.
Production type
Chemical composition (%)
| C | Si | Mn | P | S | V | W |
|---|---|---|---|---|---|---|
| On request | On request | On request | ≤ 0.03 | ≤ 0.03 | 3.7–4.5 | 5.2–6.5 |
Properties
Tungsten Carbide
Cemented tungsten carbide rings are made by powder metallurgy (sintering), with a cobalt or cobalt–nickel–chromium binder. Tungsten carbide gives the highest wear resistance of all roll materials.
It is the standard material for high-speed wire rod finishing blocks and for many reducing and sizing positions. The binder content and grain size are selected for each stand position, to balance wear resistance and toughness.
Production type
Chemical composition (%)
| WC | Co/Ni/Cr |
|---|---|
| 68–92% | 8–32% |
Properties
Need finishing Bar Rolls?
Send your drawing and stand details — we reply with a grade proposal and offer.