Csp Production The Sphc Oxide Research

This paper summarize that CSP(compact strip production) processing characters and scale's study of THCR(traditional hot continue rolling processing). In order to apply to a dependable basal research for pickling processing and improve exterior quality of CSP, the scale appearance, scale thickness distribution, structure and pickling performance of SPHC strip coil rolled by CSP processing is investigated with optical microscope, SEM, XRD and acid pickling.The appearance of the as hot coiled strip is loose and porous that is similar to THCR, but the cooled coil is more compacter opposite;the distribution of the scale thickness across the strip width is similar to THCR, the scale thickness increases from width center to edge of strip, however the increasing tendency from center to quarter is stronger than that from quarter to edge;the scale on as hot coiled strip is thicker than that one on cooled coil;The scale on button side is thicker than that one on upper side of strip;The relation of the as hot coiled strip's scale thickness X(μm) with strip thickness h(mm) is X = 3.957+2.096A , cooled coil is X = 3.684+2.209h and X= 8.152 + 3.132h is for THCR;The thickness of scale on CSP rolled coil is thinner and less sensitive to strip thickness than that by coil produced by THCR, this is more convenient than THCR.The scale composition is strongly influenced by cooling condition: the ratio Fe₂O₃: Fe₃O₄: FeO in scale on as hot coiled strip is 6.8: 33.4: 59.8. However the scale on cooled coil consists mainly of magnetite, and there is no FeO, the ratio Fe₂O₃: Fe₃O₄ is 3.6: 96.4, and. the final scale structure developed is essentially a two-layer structure with an outer hematite layer and inner magnetite layer that is difference from existed lab result obviously. The scale density calculated of as hot coiled strip and of cooled coil is 5.49 g/cm³ and 5.19 g/cm³ respectively. The scale structure on as the hot coiled across the strip width is identical essentially, but hematite on edge is slightly more than quarter and center position of cooled coil.The pickling time of as hot coiled strip is longer than cooled coil as the same thickness strip;the most difficult pickling composition is Fe3O4;total strip pickling time is as longer as strip more thickness, but the time as the thickness is not the line relation;the scale density is another important factor to pickling beside thickness and composition.