CS270618B1 - Pig iron for the production of hardened rollers - Google Patents

Abstract

The solution concerns the composition of pig iron used for the production of hardened rollers in the paper and rubber industries. It serves as a metal-bearing raw material in a cupola. The essence of the solution lies in the fact that pig iron containing 3.0 to 4.1 wt. % carbon, traces of up to 0.6 wt. % silicon, up to 0.1 wt. % sulfur, up to 0.4 wt. % phosphorus, up to 0.4 wt. % nickel and up to 0.15 wt. % chromium, is characterized by the fact that it contains manganese in the range of 0.1 to 0.6 wt. % trace elements such as lead, antimony, tin, titanium, copper and cadmium less than 0.02 wt. % and carbon occurs only in a chemically bound form as iron and manganese carbide.

Description

(57) The solution concerns the composition of pig iron used for the production of hardened rolls in the paper and rubber industries. It serves as a metal-bearing raw material in the cupola furnace. The essence of the solution is that pig iron containing 3.0 to 4.1% by weight. % of carbon, traces up to 0.6 wt. % silicon, up to 0.1 wt. % sulfur, up to 0.4 wt. % phosphorus, up to 0.4 wt. nickel and up to 0.15 A wt. % of chromium, characterized in that it contains manganese in the range of 0.1 to 0.6 wt. trace elements such as lead, antimony, tin, titanium, copper and cadmium less than 0,02% w / w and carbon occurs only in a chemically bonded form such as iron and manganese carbide.

CS 270618 Bl

CS 270618 Bl

BACKGROUND OF THE INVENTION The present invention relates to the chemical composition of pig iron used as a metal-bearing component in a cupola furnace for the production of hardened rollers used in the paper or rubber industry.

The production of hardened surface temperature controlled rollers in plants requires strict adherence to the metal charge composition of a material which forms or supports a short transition layer between the gray core and the hard surface of the rollers in the range of 450-550 ^° according to Brinell.

Currently, high purity pig iron of Sorel is used for this purpose, containing up to 4.3 wt. % carbon, up to 0.2 wt. % silicon, up to 0.03 wt. % phosphorus and up to 0.01 wt. and it is necessary to add other components to the metal charge in the cupola furnace to achieve the desired chemical composition of certain manganese and phosphorus content. The disadvantage of the current production of hardened iron cylinders of the above composition is the frequent inhomogeneity caused by the content of elements in the metal charge - mainly silicon, manganese and phosphorus. At the same time, in some cases, so-called black clusters caused by the excluded are present in the cylinder structure; carbon in the form of graphite.

These drawbacks are overcome by the use of pig iron for the production of the hardened rollers according to the invention, which is characterized in that pig iron contains 3.0 to 4.1% by weight. % of carbon, traces up to 0.6 wt. % silicon, up to 0.1 wt. % sulfur, up to 0.4 wt. % phosphorus, up to 0.4 wt. % nickel and up to 0.15 wt. % of chromium, characterized in that it contains manganese in the range of 0.1 to 0.6 wt. trace elements such as lead, antimony, tin, titanium, and cadmium have less than 0.02 wt. and carbon only in chemically bonded form such as iron or manganese carbide.

The advantage of using pig iron for the production of the hardened rollers according to the invention is that the inhomogeneity of the material caused by the inadequate content of the elements is eliminated, and black clusters and the undesirable influence of trace elements such as aluminum, lead, tin and titanium are avoided. Pig iron for the production of the hardened rolls according to the invention is for this reason a more suitable material.

In an exemplary embodiment, pig iron of the proposed composition was produced on a pilot scale and tested for use in the production of hardened rollers. Its average chemical composition was as follows: 3.1 wt. % carbon, 0.46 wt. % silicon, 0.08 wt. open,

0.035 wt. % phosphorus, 0.34 wt. % manganese, 0.12 wt. % of chromium and 0.01 to 0.001 wt. trace elements.

It is envisaged that the pig iron for the production of the hardened cylinders according to the invention can also be used to produce special cast iron for metallurgical rolls, for ductile iron castings and for piston rings. With a guaranteed silicon content of up to 0.5% by weight. in combination with a phosphorus content of max. the pig iron according to the invention can also be used in the charge of an electric induction furnace, respectively. flame furnaces for melting special cast iron for working layers of centrifugal casting cylinders.

Claims (1)

SUBJECT OF THE INVENTION Pig iron for the production of hardened rollers containing 3.0 to 4.1% by weight. % of carbon, traces up to 0.6 wt. % silicon, up to 0.1 wt. % sulfur, up to 0.4 wt. % phosphorus, up to 0.4 wt. % and up to 0.15% by weight, with a manganese content in the range of 0.1 to 0.6% by weight. trace elements such as lead, antimony, tin, titanium, copper and cadmium less than 0,02% w / w and carbon occurs only in a chemically bonded form such as iron and manganese carbide.