A composite cemented carbide roll comprising an inner layer made of an iron-based alloy, and an outer layer made of cemented carbide which is metallurgically bonded to an outer peripheral surface of the inner layer; the cemented carbide of the outer layer comprising 55-90 parts by mass of WC particles and 10-45 parts by mass of an Fe-based binder phase having a particular composition; a shaft member and a shaft end member being metallurgically bonded to at least one axial end of the inner layer; the inner layer being made of an iron-based alloy containing 2.0% or more in total by mass of at least one selected from the group consisting of Cr, Ni and Mo; and the shaft member and the shaft end member being made of an iron-based alloy containing 1.5% or less in total by mass of at least one selected from the group consisting of Cr, Ni and Mo.

There is provided a centrifugally cast composite roll for rolling having excellent wear resistance and surface deterioration resistance at levels of a high-speed steel cast iron roll and having rolling incident resistance at a level of a high alloy grain cast iron roll. A centrifugally cast composite roll for rolling having an outer layer and an inner layer, the outer layer including chemical components by mass ratio: C: 1.0 to 3.0%; Si: 0.3 to 3.0%; Mn: 0.1 to 3.0%; Ni: 0.1 to 6.0%; Cr: 0.5 to 6.0%; Mo: 0.5 to 6.0%; V: 3.0 to 7.0%; Nb: 0.1 to 3.0%; B: 0.001 to 0.1%; N: 0.005 to 0.070%; and the balance being Fe and inevitable impurities, wherein: the chemical composition of the outer layer satisfies following Formula (1), has a crystallization and precipitation amount of graphite suppressed to less than 0.3% by area ratio, and has 1 to 15% of MC carbide by area ratio; and the centrifugally cast composite roll for rolling does not have a cast defect having a diameter of ϕ4 mm or more at a boundary between the outer layer and the inner layer,

50×N+V<9.0  (1).

There is provided a centrifugally cast composite roll for rolling having excellent wear resistance and surface deterioration resistance at levels of a high-speed steel cast iron roll and having rolling incident resistance at a level of a high alloy grain cast iron roll. A centrifugally cast composite roll for rolling having an outer layer and an inner layer, the outer layer including chemical components by mass ratio: C: 1.0 to 3.0%; Si: 0.3 to 3.0%; Mn: 0.1 to 3.0%; Ni: 0.1 to 6.0%; Cr: 0.5 to 6.0%; Mo: 0.5 to 6.0%; V: 3.0 to 7.0%; Nb: 0.1 to 3.0%; B: 0.001 to 0.1%; N: 0.005 to 0.070%; and the balance being Fe and inevitable impurities, wherein: the chemical composition of the outer layer satisfies following Formula (1), has a crystallization and precipitation amount of graphite suppressed to less than 0.3% by area ratio, and has 1 to 15% of MC carbide by area ratio; and the centrifugally cast composite roll for rolling does not have a cast defect having a diameter of ϕ4 mm or more at a boundary between the outer layer and the inner layer,

50×N+V<9.0  (1).

There is provided a centrifugally cast composite roll for rolling having excellent wear resistance and surface deterioration resistance at levels of a high-speed steel cast iron roll and having rolling incident resistance at a level of a high alloy grain cast iron roll. Its outer layer includes chemical components by mass ratio: C: 1.5 to 3.5%; Si: 0.3 to 3.0%; Mn: 0.1 to 3.0%; Ni: 1.0 to 6.0%; Cr: 1.5 to 6.0%; Mo: 0.1 to 2.5%; V: 2.0 to 6.0%; Nb: 0.1 to 3.0%; B: 0.001 to 0.2%; N: 0.005 to 0.070%; and the balance being Fe and inevitable impurities, wherein: a chemical composition of the outer layer satisfies Formula (1) and has 5 to 30% of M.sub.3C carbide by area ratio; an outer layer Shore hardness (A) of a roll surface satisfies Formula (2); and a residual stress (B) of the roll surface satisfies Formula (3),

2×Ni+0.5×Cr+Mo>10.0  (1)

Hs 75≤A≤Hs 85  (2)

100 MPa≤B≤350 MPa  (3).

There is provided a centrifugally cast composite roll for rolling having excellent wear resistance and surface deterioration resistance at levels of a high-speed steel cast iron roll and having rolling incident resistance at a level of a high alloy grain cast iron roll. Its outer layer includes chemical components by mass ratio: C: 1.5 to 3.5%; Si: 0.3 to 3.0%; Mn: 0.1 to 3.0%; Ni: 1.0 to 6.0%; Cr: 1.5 to 6.0%; Mo: 0.1 to 2.5%; V: 2.0 to 6.0%; Nb: 0.1 to 3.0%; B: 0.001 to 0.2%; N: 0.005 to 0.070%; and the balance being Fe and inevitable impurities, wherein: a chemical composition of the outer layer satisfies Formula (1) and has 5 to 30% of M.sub.3C carbide by area ratio; an outer layer Shore hardness (A) of a roll surface satisfies Formula (2); and a residual stress (B) of the roll surface satisfies Formula (3),

2×Ni+0.5×Cr+Mo>10.0  (1)

Hs 75≤A≤Hs 85  (2)

100 MPa≤B≤350 MPa  (3).

A calcium-bearing magnesium and rare earth element alloy consists essentially of, in mass percent, zinc (Zn): 1-3%; aluminum (Al): 1-3%; calcium (Ca): 0.1-0.4%; gadolinium (Gd): 0.1-0.4%; yttrium (Y): 0-0.4%; manganese (Mn): 0-0.2%; and balance magnesium (Mg).

The present application discloses a nip roller, pole piece flattening equipment and a pole piece production system. The nip roller includes: a roller body. The side surface of the roller body is provided with a plurality of ridges. Each ridge is provided with a first part and a second part, where the first part is provided with part of first threads, the second part is provided with part of second threads, and a rotation direction of the first threads is opposite to that of the second threads; rotation directions of the first threads are the same, and rotation directions of the second threads are the same; and plurality of ridges are sequentially arranged at intervals in a rotation direction of the roller body, lead angles of the first threads on the first parts are sequentially decreased, and lead angles of the second threads on the second parts are sequentially decreased.

The present invention relates to a method and an apparatus for changing the effective contour of a running surface (8) of a working roller (3, 4) during the hot rolling of rolling stock in a roll stand (2) to form a rolled strip (1). The intention is to be able to change the contour of the running surface (8) during the hot rolling by means of the invention. This object is achieved according to the invention by the axial displacement of the working rollers (3, 4) in opposite directions by a displacement distance s, wherein s is greater or less than

[00001]$\frac{\Delta r}{\tan \left(\alpha \right)}$

and Δr indicates the wear of the running surface (8) in the radial direction (R) and α indicates the pitch angle of the conical portion (7) of the respective working roller (3, 4).

A vertical Pittsburgh Seam closing apparatus having a base supporting surface, a track mechanism for moving a carriage assembly which holds seam forming members used to close a Pittsburgh Seam, a pair of upper and lower guide members for guiding the duct section into a proper vertical position, and upper and lower clamping members positioned inside the duct section and adjacent the inside portion of the Pittsburgh Seam to be closed, the upper guide members and clamping member being selectively movable and adjustable for accommodating different duct section lengths. In one embodiment, the seam forming assembly includes three roller members mounted in vertical arrangement to each other, one roller member being V-shaped in configuration and the other two roller members being substantially cylindrical in shape. The V-shaped roller member may also include one or more projecting members for forming dimples in the closing process to prevent shifting and/or slipping of the closed seam.

A vertical Pittsburgh Seam closing apparatus having a base supporting surface, a track mechanism for moving a carriage assembly which holds seam forming members used to close a Pittsburgh Seam, a pair of upper and lower guide members for guiding the duct section into a proper vertical position, and upper and lower clamping members positioned inside the duct section and adjacent the inside portion of the Pittsburgh Seam to be closed, the upper guide members and clamping member being selectively movable and adjustable for accommodating different duct section lengths. In one embodiment, the seam forming assembly includes three roller members mounted in vertical arrangement to each other, one roller member being V-shaped in configuration and the other two roller members being substantially cylindrical in shape. The V-shaped roller member may also include one or more projecting members for forming dimples in the closing process to prevent shifting and/or slipping of the closed seam.