Influence of TMCP on microstructure and Properties Of 15.3mm X100 Pipeline Steel

摘要

By comparison of flow stress changing regularity of 18.4mmX80 successfully applied to production and 15.3mmX100 which is in trial,we try to find out TMCP parameters of 15.3mmX100 on the basis of mature X80 rolling parameters at 2300 hot rolling mill.Meanwhile,it analyzes the influence of deformation temperature and cooling speed during trial production at 2300mm hot rolling mill on grain refining of X100 pipeline steel.It also studies the influence of microstructure transformed by different coiling temperature,volume fraction and dimension of second phase on mechanical properties.By several rolling tests at 2300mm mill,it indicates the different deformation temperatures at rough mill and finish mill enable the structure of steel plate rolled at 2300 mm hot rolling mill to change significantly.Hardness value will be improved by different degrees.With coiling temperature decreasing,structure fining degrees at different cooling temperature will have obvious difference.By reasonable TMCP,all the yield strength of 15.3mm X100 will reach more than 690Mpa,and all the impact power at -15°C will be more than 320J.Among of them,the second phase particles,which have fine and dispersed distribution in the whole base material,have the effect of effective strengthening and significantly improve the impact roughness of X100 pipeline steel.