It is well known that the strengthening mechanisms of Nb microalloying on low carbon flat product have been widely studied and recognized since microalloying 75, but the application research and strengthening effects...It is well known that the strengthening mechanisms of Nb microalloying on low carbon flat product have been widely studied and recognized since microalloying 75, but the application research and strengthening effects of niobium on middle carbon steel like rebars have been incomplete and under argument due to some factors like limited solubility of Nb（CN） in reheating stage, dominant application of vanadium in rebars, as well as uncertain strengthening effect resulted from high rolling temperature and fast rolling speed in finishing rolling stage. Combining with new version of GB1499.2-2018： Steel for the reinforcement of concrete-Part 2： Hot rolled ribbed bars, it is very necessary to clarify the strengthening effects of niobium on high strength rebars for cost saving. In this paper, some new phenomena have been presented and discussed based on industrial trial results of Nb-bearing HRB400E, HRB500E and HRB600（E）, and then strengthening effects of niobium on high strength rebars were discussed.展开更多
A new-generation TMCP(NG-TMCP) with ultra fast cooling(UFC) as core technique was suggested instead of the conventional TMCP in which some problems are to be solved.And the ultra fast cooling technology has been succe...A new-generation TMCP(NG-TMCP) with ultra fast cooling(UFC) as core technique was suggested instead of the conventional TMCP in which some problems are to be solved.And the ultra fast cooling technology has been successfully applied to the plate rolling production in Shouqin Metal Materials Co.Ltd.Industrial trials are reported for the production of X70 pipeline steels(about 70000 t) under UFC conditions.Pipeline steels with reasonably good properties have been produced on an industrial scale.UFC can improve the temperature uniformity,the mechanical properties and the plate profile of X70 pipeline steel.The performance features of the trial plates can meet the standard of X70 pipeline steel.Spot test results have shown that the qualification rate of shape control,the performance and charpy impact properties for the trial plates are 95%,97% and 98%,respectively.The impact values of X70 pipeline steel at UFC mode exceed the standard requirements of X80 pipeline steel.The productivity is enhanced because cutting quantity of head and tail of the plate is reduced.The enhancement of control accuracy of the red back temperatures is favorable for industrial production of X70 pipeline steel.The reduced production of the steel-making has been industrially achieved,since a new composition was designed by reducing the vanadium content to less than 0.045 wt.%.展开更多
文摘It is well known that the strengthening mechanisms of Nb microalloying on low carbon flat product have been widely studied and recognized since microalloying 75, but the application research and strengthening effects of niobium on middle carbon steel like rebars have been incomplete and under argument due to some factors like limited solubility of Nb（CN） in reheating stage, dominant application of vanadium in rebars, as well as uncertain strengthening effect resulted from high rolling temperature and fast rolling speed in finishing rolling stage. Combining with new version of GB1499.2-2018： Steel for the reinforcement of concrete-Part 2： Hot rolled ribbed bars, it is very necessary to clarify the strengthening effects of niobium on high strength rebars for cost saving. In this paper, some new phenomena have been presented and discussed based on industrial trial results of Nb-bearing HRB400E, HRB500E and HRB600（E）, and then strengthening effects of niobium on high strength rebars were discussed.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2010CB630801)the National Natural Science Foundation of China (Grant No. 51104046)
文摘A new-generation TMCP(NG-TMCP) with ultra fast cooling(UFC) as core technique was suggested instead of the conventional TMCP in which some problems are to be solved.And the ultra fast cooling technology has been successfully applied to the plate rolling production in Shouqin Metal Materials Co.Ltd.Industrial trials are reported for the production of X70 pipeline steels(about 70000 t) under UFC conditions.Pipeline steels with reasonably good properties have been produced on an industrial scale.UFC can improve the temperature uniformity,the mechanical properties and the plate profile of X70 pipeline steel.The performance features of the trial plates can meet the standard of X70 pipeline steel.Spot test results have shown that the qualification rate of shape control,the performance and charpy impact properties for the trial plates are 95%,97% and 98%,respectively.The impact values of X70 pipeline steel at UFC mode exceed the standard requirements of X80 pipeline steel.The productivity is enhanced because cutting quantity of head and tail of the plate is reduced.The enhancement of control accuracy of the red back temperatures is favorable for industrial production of X70 pipeline steel.The reduced production of the steel-making has been industrially achieved,since a new composition was designed by reducing the vanadium content to less than 0.045 wt.%.
