Abstract: The preparation method includes steps of (1) melting steel according to in weight percentage 0.001-0.003% of C, 5.0-6.6% of Si, 0.2-0.3% of Mn, 0.05-0.12% of Al, 0.01-0.04% of V, 0.03-0.06% of Nb, 0.02-0.03% of S, 0.009-0.020% of N, O which is less than or equal to 0.0020%, and the balance being Fe and unavoidable impurities; (2) forming cast strips after a thin-strip casting course; (3) hot-rolling the cast strips under inert atmosphere conditions; (4) cooling the hot-rolled cast strips to 550-600 DEG C., coiling and performing low-temperature hot rolling/warm rolling on the coiled cast strips under a nitrogen atmosphere condition; (5) removing oxidized scales though pickling, performing cold rolling multiple times; (6) performing recrystallization annealing, coating with an MgO layer, and coiling; (7) performing purification annealing under hydrogen circulation conditions; and (8) removing oxidized scales, coating with an insulating layer, performing flat stretch annealing, and air-cooled coiling.

Abstract: The present disclosure discloses a comb polymer or a salt thereof, wherein the structural formula of the comb polymer containing the following constitutional units. When the comb polymer provided in the present disclosure is used in a water-based drilling fluid as a filtration control agent, it can eliminate the defects of conventional filtration control agents which would be subject to ineffectiveness under high temperature and high salinity conditions. The comb polymer has high temperature and salt resistance, and can be produced through simple processes at comparatively low costs. When the comb polymer provided by the present disclosure is used as a filtration control agent, even being added into the drilling fluid at a comparatively low amount, it can still present rather good effects in lowering the amount of filter loss.

Abstract: The preparation method includes steps of (1) melting steel according to in weight percentage 0.001-0.003% of C, 5.0-6.6% of Si, 0.2-0.3% of Mn, 0.05-0.12% of Al, 0.01-0.04% of V, 0.03-0.06% of Nb, 0.02-0.03% of S, 0.009-0.020% of N, O which is less than or equal to 0.0020%, and the balance being Fe and unavoidable impurities; (2) forming cast strips after a thin-strip casting course; (3) hot-rolling the cast strips under inert atmosphere conditions; (4) cooling the hot-rolled cast strips to 550-600 DEG C, coiling and performing low-temperature hot rolling/warm rolling on the coiled cast strips under a nitrogen atmosphere condition; (5) removing oxidized scales though pickling, performing cold rolling multiple times; (6) performing recrystallization annealing, coating with an MgO layer, and coiling; (7) performing purification annealing under hydrogen circulation conditions; and (8) removing oxidized scales, coating with an insulating layer, performing flat stretch annealing, and air-cooled coiling.

Abstract: The present disclosure discloses a comb polymer or a salt thereof, wherein the structural formula of the comb polymer containing the following constitutional units. When the comb polymer provided in the present disclosure is used in a water-based drilling fluid as a filtration control agent, it can eliminate the defects of conventional filtration control agents which would be subject to ineffectiveness under high temperature and high salinity conditions. The comb polymer has high temperature and salt resistance, and can be produced through simple processes at comparatively low costs. When the comb polymer provided by the present disclosure is used as a filtration control agent, even being added into the drilling fluid at a comparatively low amount, it can still present rather good effects in lowering the amount of filter loss.