Casting into the bending or straightening zone will also cause the edge cracking problem during the deformation of the pickling seamless pipe.
0Cr15mm9Cu2nin and 0Cr17Mm6ni4Cu2N stainless steel belong to 200 series austenitic stainless steel, which is different from traditional 200 series and 300 series austenitic stainless steel. This kind of 200 stainless steel square tube is prone to edge cracks, surface cracks, The problem of poor molding quality of edge damage. In the actual hot rolling production, the two steel types adopt 200 series heating curves, and the furnace temperature is controlled at 1215-1230C. Its thermal system implements the second-level computer model “Rough Rolling Regulations” and “Finish Rolling Regulations”. 800-1020C. Referring to the actual hot rolling process of two pickling seamless pipe, formulate the heating system and deformation temperature of this test method, and then carry out the simulated hot rolling test on the hot rolling test device designed and manufactured by ourselves. Today’s information of the square pipe association: using AOD+LF refining process to produce 0Cr15Mm9Cu2Nn and 0Cr17I6ni4Cu2N pickling non-vascular continuous casting bad continuous casting through vertical bending continuous casting process, the cross-sectional size of the continuous casting bad is 220m1260m. The mass fraction % is shown in the table. The microstructure of the bad shell at different depths of 0Cr15m9Cu2Nn acid-washed non-vascular continuous casting, as shown in the figure, corresponds to the depth of the cast bad shell. When an abnormal situation occurs and the temperature of the edge of the casting fails to drop to the low-temperature brittle range. The microstructure at 15 and 25m. The shape of the microstructure and the grain size of the 20g high-pressure boiler tube will increase with the depth of the slab shell. Changes, but show a certain difference. At the shell depth d0m, the microstructure is mainly a skeleton-type dendrite structure, and the primary and secondary dendrite spacing is small. At d5mm, it is mainly a dendrite structure.
Dendrite spacing is large. At d>15mn, the dendrites are worm-like, but at d25m, they are mainly cellular crystals. The microstructure of the Cr17Im6ni4Cu2N square tube continuous casting slab in Fig. 1 shows that the continuous casting bad shell is basically a dendrite structure. Although there are certain differences in the dendrite morphology, its structure is mainly composed of a gray austenite matrix, and black ferrite. Like the 0Cr15Mn9Cu2Nin square tube, as the depth of the shell increases, the primary and secondary dendrite spacing gradually increases, and the dendrite shape changes from a skeleton to a worm. , the plastic behavior in the process of martensitic phase transformation in wear-resistant composite steel pipes was experimentally analyzed, and the austenite grain size and its austenite grain growth law, martensite orientation, phase transformation plasticity, Effects of stress and morphology on the mechanical properties of wear-resistant composite steel pipes. Under the condition of temperature 1010 austenitization 15mir, the start temperature point s and end temperature point ㎡ of martensitic transformation increase with the increase of austenitization temperature, and the parameters in the phase transformation plastic model of wear-resistant composite steel pipe change with increases with increasing equivalent stress. When the austenitization temperature is lower than 1050C, the grain growth shows a normal growth process. With the increase of austenitization time, the round steel s increases. -3500 thermal simulator, the plastic behavior of the wear-resistant composite steel pipe during the martensitic transformation process was experimentally analyzed, and the austenite grain size and its austenite grain growth law were studied, and the martensite Effects of orientation, phase transformation plasticity, stress and morphology on the mechanical properties of wear-resistant composite steel pipes. Under the condition of 1010 austenitization for 15 minutes, the start temperature point s and end temperature point ㎡ of martensitic transformation increase with the increase of austenitization temperature, and the parameter K in the phase transformation plasticity model of wear-resistant composite steel pipe increases with the equivalent stress. When the austenitizing temperature is lower than 1050C, the grain growth shows a normal growth process. As the austenitizing time increases, Is increases, and the B-phase transformation is divided into grain boundaries. The nucleation and growth of phases and There are two stages of nucleation and growth of Widmanite a. phase. When the cooling rate is increased from 0.1C/s to 150C/s, the phase transformation process of B+a and + mainly occurs in the Ti-55 alloy. The grains in the wear-resistant composite steel pipe can still remain uniform and small, and the martensite Fine coherent complex carbides were precipitated on the surface. Using transmission electron microscope, scanning electron microscope, x-ray diffractometer and electrochemical methods to study the microstructure and electrochemical properties of wear-resistant steel pipe alloys in different states such as cast state, homogenized state, and vehicle state, and electron probe EPM The morphology and composition of the main precipitates in wear-resistant steel pipe annealed at 150-300C were investigated by energy spectrum analysis.
Post time: Mar-30-2023