State of the Art in the Control of Inclusions in Tire Cord Steels and Saw Wire Steels – A Review

Abstract

Non-metallic inclusions in tire cord steels and saw wire steels often act as breakage source during cold drawing and standing process. In this work, the control of inclusions in tire cord steels and saw wire steels in the production process are extensively reviewed. On the one hand, the new perspectives on the problems left over in the past have been discussed comprehensively, include the new understanding of the origins of SiO 2 -CaO-Al 2 O 3 system inclusions, the new found of evolution of inclusions in cord steel and saw wire steel during rolling and drawing process, and the new understanding of controlling the plasticity of inclusions. On the other hand, the new approaches of controlling inclusions in tire cord steels and saw wire steels have also been discussed, include alkali oxides treatment, boron treatment, Mg treatment and cerium treatment. R 2 O (R ¼ K, Rb, Cs) containing refining slag can significantly improve the cleanliness of saw wire steels and saw wire steels. Adding alkali oxides, boron or Mg into molten steel can dramatically improve the deformability of inclusions through expanding the acreage of the region with low melting points. The basicity of top slag at the range of 1.1-1.2, and ωAl 2 O 3 in top slag around 3 wt% in order to control the composition of inclusions in the region with low melting points when ZrO 2 -based refractory be used to reduced the pure Al 2 O 3 inclusions in tire cord steel. Finally, the unsolved problems are summarized.

State of the Art in the Control of Inclusions in Spring Steel for Automobile - a Review

“…This issue have been reviewed by our previous work. 142) In summary, the composition of inclusions should be controlled in the region with a high SiO 2 content and extremely low Al 2 O 3 content (but not the low melting temperature area) due to that the deformability of inclusions at low temperature (during drawing process) is the best.…”

“…Steel Owing to the strong ability of deoxidization and desulphurization of rare earth, it have been used to treated spring steel. 108,135,[143][144][145][146][147][148] The recent advance research on the effect of rare earth modify inclusions in spring steel was done by professor Lai et al [136][137][138][139][140][141][142][143][144][145][146][147] They studied the effect of rare earth yttrium (Y) on inclusions in spring steel, the result indicated that Al 2 O 3 inclusions was transformed to YAlO 3 . In addition, the main inclusions are Y 2 O 3 , Y 2 O 2 S, Y 2 S 3 and the average diameter of inclusions decreased sharply after modified by rare earth yttrium (Y).…”

Effect of Al₂O₃ on Evolution of Oxide Inclusions in Tire Cord Steel during Hot Rolling

“…Oxide inclusions in tire cord steels are one of the main reasons for wire fracture during the drawing process. [1][2][3][4] The requirements of higher strength and smaller diameter in tire cord steel demand wire rods with higher cleanliness as well as with excellent drawability. Tire cord steels is typically a silico-manganese deoxidized steel.…”

“…Because the ferroalloy used in actual production contains a certain amount of impurity elements together with the influence of refractory and slag, the composition of inclusions in molten steel will inevitably change and almost all inclusions in tire cord steels correspond to the SiO 2 -MnO-Al 2 O 3 -CaO system. [2][3][4][5] In view of the fact that it is impossible to remove the inclusions completely and, on the other hand, deformable inclusions with low melting point are beneficial for the drawability of steel wires, more researches 2,[6][7][8][9][10][11][12][13][14][15] are focused on the influence of liquid steel composition, refining slag, and refractories on inclusions of SiO 2 -MnO-Al 2 O 3 -CaO system, which is expected to control the inclusions in the low melting point regions.…”

Feasibility of using Continuously Cast Round Bloom as a Substitute to Cast Ingot in the Manufacture of Heavy Forgings

“…The primary type of internal defect in such strands is the formation of a central shrinkage cavity, which is particularly prone to occur in large-section blooms. [9][10][11] Such defects must be eliminated to ensure a final product with suitable mechanical performance. When a CC strand solidifies, solutes present in the liquid will be enriched as a result of redistribution between the solid and liquid phases, involving the flow of molten steel-enriched solutes between dendrites as a result of the negative pressure of solidification shrinkage or bulging, which in turn leads to macrosegregation.…”