The High Temperature Mechanical Properties Of Ferritic Stainless Steel Billet

Continuous casting of steel is an important production technique to link up steel making and rolling,and the quality of continuous cast slab has important influence on the final product quality of steel. The statistic show that,more than fifty percent defect of slab related to crack.The cracking of solidified shell due to slab's mechanical properties and their change rules in high temperature.Therefore,research on high temperature mechanical properties of slab has great significance for controlling andimproving the quality of slab.Stress strain curve,yield strength,tensile strength,hot ductility,elastic limit,modulus of elasticity and plastic modulus with temperature of steel 409L and steel 430,which produced by the slab caster in a certain steel plant, have been measured in the temperature range of 300-1150℃by the hot tensile test technique with Daojin AG-10 system. According to the hot ductility curve,the brittle zone of steel 409L and steel 430 were found. The results of the test show that the first brittle zone of steel 409L is about above 1150℃;for steel 430, the third brittlezone ia about between 700℃and 900℃.In order to further understand the high temperature mechanical properties of slab, he organization and microstructure of the two steel fracture specimen with high-temperature tensile were systematically studied.The results showed that the recrystallization temperature of 409L is about 900℃,the grain growth of 409L occurred at 1000℃and the 409L with high temperature deformation are ferrite single-phase state, no austenite;the recrystallization temperature of 430 is probably around 800～900℃,the grain growth of 430 occurred at 1100℃.The 409L with high temperature deformation will experience austenite and ferrite dual-phase zone, the temperature range 800～1150℃.For the high temperature tensile,the calculation of true stress-strain has been a hot research topic. With the high temperature tensile test data, the calculation methods and formulas were summarized and amended, and the program of True stress-True strain Calculation and Analysis Software were compiled by VB (TTCAS).