Method for manufacturing pipeline steel medium plate with excellent tenacity through normalizing rolling

• Main Authors: XU XIAODONG, MA QINGSHEN, LI SHAOPO, LI YONGDONG, JIANG ZHONGHANG, CHA CHUNHE, DING WENHUA, WANG WENJUN, BAI XUEJUN, LI JIADING
• Format: Patent
• Language: Chinese; English
• Published: 30.05.2012
• Subjects: CHEMISTRY; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS

The invention relates to a pipeline steel and a manufacturing method thereof, in particular to a method for manufacturing a pipeline steel medium plate with an excellent tenacity through normalizing rolling. The method comprises the steps of: heating a bloom steel for 3 to 6 hours under low temperature from 1120 to 1220 DEG C, hot rolling the bloom steel after being discharged and naturally cooling the rolled bloom steel to the room temperature, wherein the hot rolling is divided into two stages and holding delay is operated between the two stages; the first stage of longitudinal rolling ensures a single-path depressing ratio more than 15%; the holding delay thickness of a semi-finished product is less than or equal to two times of the thickness of the finished products; and the temperature for ending the rolling in the second stage is Ac3 plus (30 to 80) DEG C. The method has the advantages that the production process is simple, the steel plate has excellent low-temperature tenacity,an impact power of a -60