Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C33/00—Making ferrous alloys
  • C22C33/003—Making ferrous alloys making amorphous alloys

Definitions

• steel refining agents e.g. metals or ferro alloys
• This invention relates to a method of producing a sinter product having a high nitrogen content together with steel refining substances, particularly ferro alloys.
• the nitrogen content of the nitrated steel is relatively poor.
• a sinter product containing nitrogen and steel refining substances notably ferro-alloys.
• a particular advantage for using such sinter alloys is that concurrently with the process of nitration refining substances are introduced into the steel, and also that the use of particulate sinter enables them to be used without causing discomfort to the foundrymen by the generation of dust.
• the high specific gravity of the sinter assures better penetration into the steel melt resulting in a more homogeneous distribution of the nitrogen.
• the production of a previously known process for such sinter products included heating an initial mixture of calcium carbide and steel refining substances by the external application of heat, and exposing the mixture to a nitrogen atmosphere.
• This process may be performed for example by filling reaction vessels e.g. shallow baths or tubes, and placing the filled reaction vessels on or into powdered calcium carbide used for the production of lime-nitrogen.
• the heat of reaction generated by the calcum carbide surrounding the baths or tubes during the formation of lime-nitrogen heats the mixture contained inside the baths of tubes from the outside.
• sinter products may be obtained having a high nitrogen content, together with steel refining substances, and which provide an available nitrogen yield of from two to three times that obtained with sinters as herein-before described.
• the invention consists of a method of producing a sinter product having a high nitrogen content together with one or more steel refining agents, in which a homogeneous reaction mixture of finely powdered calcium carbide and crushed steel refining agents is raised to reaction temperature by local heating at points in the inter- -nited States Patent Cir ior of the mixture while the mixture is under a nitrogen atmosphere.
• the starting materials are homogenised by thorough mixing using for instance bladed mixers, rotary drum mixers, gravity mixers and screw mixers, and then filled into reaction vessels and points in the interior of the mixture raised to reaction temperature.
• the local points in the interior of the mixture are distributed to provide from 3 to 5 points per square metre of cross section of the charge.
• the reaction temperature of for example 1100 to 1300 C. may be attained by ignition at localized points within the reaction mixture of an igniting mixture or by electrical resistance heating.
• igniting mixtures mixture of alkaline-earth carbides and oxygen-supplying substances have proven to be particularly suitable.
• the charge of starting materials preferably consists of mixtures of 10 to 50 percent by weight, praticularly 30 to 40 percent by weight, of steel refining agents, the remainder being commercial calcium carbide containing at least 65% and preferably 72 to 74%, of calcium carbide.
• the grain size of the calcium carbide used is preferably below 0.5 mm., particularly below 0.1 mm.
• the grain size of the steel refining agents is preferably likewise below 0.5 mm., particularly below 0.24 mm.
• the steel refining agents may be metals, or particularly ferro-alloys such as for example ferro-manganese and ferro-chromium (types affine, surafiine and carb-ure), or ferro-vanadium, ferro-niobiurn-tantalum, ferro-manganese-vanadium, ferro-titanium, ferro-nickel.
• ferro-alloys such as for example ferro-manganese and ferro-chromium (types affine, surafiine and carb-ure), or ferro-vanadium, ferro-niobiurn-tantalum, ferro-manganese-vanadium, ferro-titanium, ferro-nickel.
• the method of the invention may be performed either batch-wise or continuously, in suitable reaction vessels, such as for example cementation furnaces and tunnel furnaces, if the process is performed in a tunnel furnace, the mixture is loaded on mobile reaction trucks, ignited and conveyed through the tunnel furnace under a nitrogen atmosphere. Individual trucks carrying only calicum carbide may be sent through the tunnel furnace between the trucks charged with the reaction mixture.
• suitable reaction vessels such as for example cementation furnaces and tunnel furnaces
• igniting points were prepared from the top, evenly distributed over the cross section, for the reception of an igniting mixture consisting of a commercial calcium carbide and calcium nitrate in a 1:1 proportion by weight, and introduced in quantities of 2 to 3 kg. per igniting point. After ignition the truck was continuously passed through a tunnel furnace in which a nitrogen pressure of 200 mm. water column, was maintained.
• a method of producing a sinter product having a high nitrogen content together with one or more steel refining agents the steps of forming a homogeneous reaction mixture of finely powdered calcium carbide, and one or more crushed steel refining agents, then heating the said mixture to reaction temperature by local heating at a plurality of spaced points in the interior of the mixture while the mixture is under a nitrogen atmosphere, whereby a sinter product is obtained.
• reaction mixture is raised to reaction temperature at from 3 to 5 localized heating points per square metre of cross section.
• reaction temperature is attained by ignition with the aid of electrical resistance heating at the said localized heating points.
• the said homogeneous reaction mixture is a reaction mixture of a calcium carbide and one or more steel refining agents.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Manufacture And Refinement Of Metals (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7128329

Family Applications (1)

Country Status (4)

Cited By (1)

Citations (6)

Family Cites Families (2)

• 1966
  • 1966-07-02 DE DE19661533257 patent/DE1533257B1/de not_active Withdrawn
• 1967
  • 1967-06-30 CS CS4833A patent/CS167868B2/cs unknown
  • 1967-06-30 US US650175A patent/US3472655A/en not_active Expired - Lifetime
  • 1967-06-30 NO NO168871A patent/NO118277B/no unknown

Patent Citations (6)

Also Published As

Similar Documents