Full-service roll & mill component solutions
Bowers & Jones manufacture rolls and wheels for copper rod mills and continuous rotary extrusion machines. Produced in a range of high performance steel grades, our products offer the customer much improved properties compared to conventional tooling, for a stable manufacture and longer service life.
These highly stressed rolls must offer a high hardness and wear resistance with the lowest possible tendency to pick up. Rolls made from our cold work tool steels are most suitable for these applications.
Due to the very high pressure loads occurring during the straightening of round bar material, the journals of the rolls are highly stressed. In order to improve the resistance to breakage, two alternative hardening processes are available at Bowers & Jones:
For some applications, composite rolls are offered as a two part design: the working part of the roll is a shell made from ZESEK or ZESEK EXTRA fitted onto a shaft made from tough engineering steel. The choice of the best suitable option depends on customers’ requirements.
A combination of ZESEK materials and our specific heat treatment processes gives Bowers & Jones rolls a much better stability compared to cast materials. Customers then benefit from a better
performance and much lower service life costs.
Our machining range allows us to manufacture extra-large rolls
up to 1350mm diameter roll body and up to 3000mm length shafts, up to a combined weight of 8 tonnes.
Our technical staff will be happy to give you further advice on
design and material selection.
ZESEK, W. Nr. 1.2379 (~AISI D2) is a forged ledeburitic high carbon high chrome cold work tool steel alloyed with Mo and V. Compared to cast D2, ZESEK has no porosity or other casting defects which increases its crack resistance.
ZESEK EXTRA a further development of the well-known tool steel ZESEK with very similar chemical composition but with a more homogeneous microstructure.
Characteristics:
Ledeburitic 12% Cr steel with excellent toughness, very high wear resistance, and cutting edge retention. Using a hardening
temperature of 1060-1080ºC (secondary hardening) and double tempering, the steel can be nitrided.
Typical Applications:
Hot working tool steel for highest requirements:
Because of its very good high-temperature strength and toughness, the steel is excellent for highly stressed hot work tooling, e.g. for extrusion tooling, hot forming rolls or copper rod rolls.
| Nominal Analysis | C | Si | Mn | Cr | Mo | V | |
|---|---|---|---|---|---|---|---|
| ZESEK | 1.55 | 0.25 | 0.30 | 11.75 | 0.70 | 1.00 | % |
| ZESEK EXTRA | 1.55 | 0.30 | 0.40 | 11.50 | 0.70 | 0.80 | % |
Heat Treatment
| Annealing | 820–850ºC |
|---|---|
| Annealing hardness | max, 255HB |
| Stress relieving | 650ºC |
| Hardening | 1000–1040ºC/air, oil or hot bath 500–550ºC |
| Secondary hardening | 1060–1080ºC/air, oil or hot bath 500–550ºC |
| Tempering | see tempering graph; at least twice after secondary hardening |
Due to the fine and more homogenous structure (see Fig. 2) the chipping resistance has been enhanced for a longer roll life. Because of the better distribution of primary carbides the abrasive wear resistance is slightly better compared to conventional W. Nr. 1.2379.
By using Bowers & Jones’s special heat treatment the steel can also be used in selected hot rolling applications.
| Roll Type | Recommended materials | Material No. | AISI (ASTM) | Usual hardness HRc | Tensile strength Rm=N/mm² | Hardening process SH = Surface hardening, TH = Through hardening |
|---|---|---|---|---|---|---|
| Straightening rolls for Bars (one or two part design) | ZESEK | 1.2379 | D2 | 56 – 62 | – | SH + TH |
| Straightening rolls for Bars (one or two part design) | SRSE | 1.2714 | L6 | 56 – 59 | – | SH |
| Straightening rolls for Bars (one or two part design) | ZESEK EXTRA | – | – | 56 – 62 | – | SH + TH |
| Straightening rolls for Tubes (one or two part design) | ZESEK | 1.2379 | D2 | 56 – 62 | – | SH + TH |
| Straightening rolls for Tubes (one or two part design) | SRSE | 1.2714 | L6 | 56 – 59 | – | SH |
| Straightening rolls for Tubes (one or two part design) | ZESEK EXTRA | – | – | 56 – 62 | – | SH + TH |
| Shafts for two part rolls | SRSE | 1.2714 | L6 | – | 900 – 1100 | – |
| Shafts for two part rolls | 30CrNiMo8 | 1.6580 | – | – | 800 – 1200 | – |
| Shafts for two part rolls | 34CrNiMo6 | 1.6582 | – | – | 800 – 1200 | – |
| Shafts for two part rolls | 40CrNiMo6 | 1.6565 | 4340 | – | 800 – 1200 | – |
| Shafts for two part rolls | 42CrMo4 | 1.7225 | 4140 | – | 750 – 950 | – |
| Straightening rolls for Rails | ZESEK | 1.2379 | D2 | 58 – 60 | – | TH |
| Straightening rolls for Sections | ZESEK | 1.2379 | D2 | 58 – 60 | – | TH |
Our team of experienced technical staff is always on hand to provide expert assistance, consultation, and advice to our valued customers.
Whether you have questions about our roll tooling products, need help troubleshooting an issue with your mill equipment, or require guidance on the best practices for maintenance and operation, our knowledgeable and ISO 9001 certified team is here to help.
