Azovstal Metallurgical Combine Research Articles

Industrial Testing of Group IV Hardness Grinding Balls Produced by Donetsk Metal Rolling Plant

Results are given for a complete processing scheme for manufacturing small diameter grinding balls of hardness groups III and IV produced from small cross-section continuously-cast carbon steel billet. The steel chemical composition and rolling and heat treatment regimes proposed have made it possible to produce balls of grinding hardness groups III and IV since the beginning of mastering ball rolling mill 30–80. Industrial tests of grinding balls 40 mm in diameter of hardness group IV performed under Southern Mining and Processing Plant conditions demonstrate that grinding efficiency of finished class size –0.074 mm is better by 3.1% higher and specific consumption of grinding balls is 8.83% lower than in the case of using grinding balls of hardness group III produced by DMKD or Azovstal Metallurgical Combine.

Accelerated Cooling After Controlled Rolling During Heavy Plate Pipe Steel Manufacture in 3600 Mill at the Azovstal Metallurgical Combine

Contemporary controlled rolling technology with accelerated cooling is assimilated at the Azovstal Metallurgical Combine, used in production of plate intended for manufacturing gas and oil pipelines of considerable diameter. General characteristics are provided for the SMS-Demag accelerated controlled cooling unit in the plate workshop within the 3600 mill line. Mechanical properties are tested and the microstructure is examined. Batches of pipe steels of various grades satisfy test specifications and are estimated as favorable according to results for pipes manufactured from them.

Improving the Design of the Oxygen Lance and the Blowing Regime for BOF Steelmaking in the BOF Shop at the Azovstal Metallurgical Combine

Newly designed tips for oxygen lances and new blowing regimes for BOF steelmaking have been developed, tested, and introduced in the BOF shop at the Azovstal Metallurgical Combine (part of the Metinvest Holding Company, Ltd.). The new tips and regimes improve the performance indices for steel production under different charging and operating conditions in the shop.

Operation of Blast Furnaces at the Azovstal Metallurgical Combine with a Uniform Circumferential Distribution of the Charge and the Gases

Results are presented from the operation of three blast furnaces equipped with a Tarasov calibrator at the Azovstal Metallurgical Combine. Use of the calibrator ensures uniform circumferential distribution of the charge materials and furnace gases.

Improving the Charging and Blast Regimes on Blast Furnaces at the Azovstal Metallurgical Combine

An examination is made of the main problems and methods of optimizing the gasdynamic regime of blast furnaces. The gasdynamic regime depends mainly on the distribution of materials in the top of the furnace. The interactive system CHARGING – which models charging by a bell-less charging apparatus – is used to determine the configuration of the layers of charge materials and calculate the distribution of burden coke along the radius of the top. Improvements were made to the charging regimes on blast furnaces Nos. 3 and 4 at the Azovstal Metallurgical Combine. The blast parameters of the furnaces at the combine were optimized by using the interactive BLAST system. This system used the parameters specified for the blast to calculate generalizing characteristics of the blast regime and correct the blast parameters as needed in order to keep the generalizing characteristics at their optimum levels.

Improvement of Railway Rail Manufacturing Technology

Manufacturing technology is developed for railway rails from converter steel under the Azovstal Metallurgical Combine conditions, including steel melting in a converter and treatment in a furnace-ladle unit, pouring steel into a mold, rolling ingots and billets, and rail surface hardening with high-frequency current heating. Testing of an adapted batch of rails type R65 made from converter steel K76F showed that the technology developed provides rail properties in accordance with the specifications of DSTU 4344:2004. Industrial manufacture and supply is started for R65 type thermally hardened rails made from converter steel K76F.

Reduction in Slab Surface Corner Crack Damage due to Development of Rational Secondary Cooling Regimes

The effect of heating condition for continuously-cast slabs of different cross section on the probability of corner crack formation is analyzed. Versions are considered for correction of cooling water and air flow rates in secondary cooling zone (SCZ) sprayers with the aim of optimizing the thermal profile of continuously-cast billets poured from crack-resistant steels. SCZ operating regimes are developed for the Azovstal Metallurgical Combine CBCM-6 making it possible to reduce the overall level of slab surface cleaning by 30%.

Experience of using accelerated cooling in production of steel X70 plate for the Central Asia – China gas pipeline

At the Azovstal Metallurgical Combine together with the Bardin Central Research Institute of Ferrous Metallurgy production of thick plate (3266 × 19.1 mm) is being developed for a large diameter gas pipeline of strength category X70. Plates are manufactured using controlled rolling technology with accelerated cooling (CR + AC) instead of previous controlled rolling technology with air cooling. Introduction of CR + AC promotes an increase in average values of energy for failure KV with impact tests on finished metal plate, and also a marked improvement in 3600 rolling mill productivity.

Steel plate Kh80 with high impact strength for gas pipelines

At the Azovstal Metallurgical Combine together with the Bardin Central Research Institute of Ferrous Metallurgy a sheet steel up to 25 mm thick alloy system, steel melting technology, and a controlled rolling regime are developed, providing preparation of mechanical properties meeting the specifications laid down for steel Kh80 pipe production. The possibility is demonstrated of producing with existing equipment thick rolled sheet for gas pipelines of considerable diameter of strength category Kh80 with high impact strength (KV at –20 °C ≥ 200 J, KCV at –20 °C ≥ 250 J/cm2) and brittle failure resistance (proportion of ductile component in DWTT specimen fracture at –20 °C ≥ 95 %).

Development of slag-forming mixtures based on fused fluxes for continuous casters Nos. 3–5 at the Azovstal Metallurgical Combine

A method is presented for determining the physical properties of slag-forming mixtures (SFM) for the continuous casting of steel. Results are reported from studies performed to determine the chemical composition of SFM for casting of peritectic low-alloy steels on a curvilinear continuous caster at the Azovstal Metallurgical Combine. A study is made of the quality of flat-rolled products obtained from slabs cast with the use of SFM of different chemical compositions.

Prospects of the technology used to make skelp at the Azovstal Metallurgical Combine

An analysis is made of the state of the technology used at the Azovstal Metallurgical Combine to produce skelp. The prospects for further development of the technology are discussed along with the reconstructive measures such improvement would require in the converter and plate shops, the objective being to master the production of skelp of strength classes X90–X120. An evaluation is made of how the quality indices of skelp made for the production of electric-welded pipe would be affected by the implementation of such measures and changes to the manufacturing technology.

Improving the hardness of OAO Azovstal Metallurgical Combine steel balls for crushing mills

Improving the hardness of OAO Azovstal Metallurgical Combine steel balls for crushing mills