Tungsten carbide, HSS and tool steel rings for high-speed blocks.
High-speed no-twist finishing blocks and reducing/sizing blocks in wire rod mills run at very high speeds with small passes. The ring must have very high wear resistance and keep a good surface for a long time.
Tungsten carbide is the standard material for these positions. HSS and tool steel grades are an alternative for selected positions.
- No-twist finishing blocks
- Pre-finishing blocks
- Reducing and sizing blocks
- Pinch and looping rolls (tool steel)
Available grades
Material grades
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 wire Rod Block Rings?
Send your drawing and stand details — we reply with a grade proposal and offer.