Generally the pattern is
- Work Rolls – 61/63 HRC or higher
- 1st intermediate rolls – 57/59 HRC
- 2nd intermediate rolls – 58-60 HRC
The rolls are heat-treated in salt baths which impart good uniformity of hardness.
Z Hi Rolls
The work rolls are mostly made of AISI D2, M1, M2 grades. Support rolls are in D2. Drive rolls are made from 3% Cr steel, sometimes 1.2362.
4 Hi, 6 Hi Rolls
Dee Tee manufactures 4 Hi/6 Hi Rolls with multiple advantages of long life and higher performance under pressure for cold rolling of almost all types of metals-ferrous, non-ferrous, SS, aluminum, silver, gold etc. It includes Work Rolls, Intermediate Rolls, Backup Rolls and Skin Pass Rolls.
The rolls are subject to high wear and tear, heavy bending loads and high roll separation forces
Mill incidents and accidents are a common phenomenon and induce heavy amount of stresses in the rolls. The roll material therefore has to be of very good quality. Dee Tee mostly purchases raw material directly from renowned manufacturers having integrated melting–forging facilities.
- Grades – 52100, 3% Cr, 1.2327, D3, D2
- Size Range – Maximum length 3.5 meters, maximum dia 550 mm, maximum weight 3 tons.
Sendzimir Mill Rolls
20 Hi Rolls: Sendzimir Mills are mostly used in SS and non-ferrous Cold Rolling. The small diameter rolls allow superior reductions on very hard materials to very thin gauges. Also, they help to maintain very close gauge tolerances. Due to high mill speeds and materials rolled being hard, the rolls have to be tough with good wear resistance. The work rolls are generally made of AISI D2 (1.2379), M1 (1.3346), M2 (1.3343) grades. For some high end applications, powder metallurgy grades are also used. The 1st and 2nd intermediate rolls are mostly made of 5% Cr. tool steel grades (Din 1.2362 or H11 or H13) and sometimes D2 (1.2379) material.