P-added high strength IF steel M250P1 is widely used in vehicle body and safety parts because of its good mechanical performance and forming properties.Experiments of high power laser welding of 4.8 mm thick P-added h...P-added high strength IF steel M250P1 is widely used in vehicle body and safety parts because of its good mechanical performance and forming properties.Experiments of high power laser welding of 4.8 mm thick P-added high strength IF steel M250P1 is performed by using a 12 kW CO_2 laser.In order to investigate the effects of phosphorus in high strength steel on the quality of welding,the Cupping and tensile tests,optical and SEM energy dispersive spectrometer analysis have been done on three welded joints.Some results have been obtained below.In the given welding parameters,the welded joints show good tensile and forming properties.However,it has been also found that the cracking is easy to occur in the fusion zone of welded joint during deformation.Some research works have been done.The results show that the fast cooling of fusional metal leads to the phosphorus microsegregation in the fusion zone because of relative low diffusion rate of phosphorus,which brings about the poor toughness of welded joints.展开更多
Since it has excellent tensile strength, the quenching and partitioning （Q ＆ P） treated steel has been widely acclaimed. Some researched is currently being conducted on Q ＆ P steel, but Q ＆ P techniques and relat...Since it has excellent tensile strength, the quenching and partitioning （Q ＆ P） treated steel has been widely acclaimed. Some researched is currently being conducted on Q ＆ P steel, but Q ＆ P techniques and related mechanisms have been mostly research based on conventional transformation-induced plasticity （TRIP） steel. This study researches the effect of Mn on the properties of Q ＆P sheet steel. Two kinds of steel sheet with different levels of Mn content （1.46% Mn and 2.75% Mn） are investigated. After being fully annealed, the steel sheets were quenched to a temperature between Ms and Mr. Allocation treatment then caused the carbon to be partitioned into the remaining austenite.The microstructure and tensile properties were analyzed. The results show that the increment of Mn content can increase the stability of the steel and decrease the sensitivity of the quenching temperature （QT）. The results also indicate that increasing the level of Mn can effectively suppress the formation of bainite.展开更多
对试验用淬火配分(Quenching and Partitioning,Q&P)钢在一步淬火配分工艺中不同淬火温度(220、260、300℃)和淬火时间(60、120、180 s)下组织、织构、力学性能及拉伸断口特征进行研究.结果表明:试验用Q&P钢在一步淬火配分中获...对试验用淬火配分(Quenching and Partitioning,Q&P)钢在一步淬火配分工艺中不同淬火温度(220、260、300℃)和淬火时间(60、120、180 s)下组织、织构、力学性能及拉伸断口特征进行研究.结果表明:试验用Q&P钢在一步淬火配分中获得的最大残余奥氏体体积分数为7.12%;随着淬火温度升高,板条马氏体的宽度增大;随着淬火温度和配分时间升高,织构的最大强度逐渐降低,抗拉强度逐渐减少;屈服强度和延伸率呈相反的变化趋势.展开更多
文摘P-added high strength IF steel M250P1 is widely used in vehicle body and safety parts because of its good mechanical performance and forming properties.Experiments of high power laser welding of 4.8 mm thick P-added high strength IF steel M250P1 is performed by using a 12 kW CO_2 laser.In order to investigate the effects of phosphorus in high strength steel on the quality of welding,the Cupping and tensile tests,optical and SEM energy dispersive spectrometer analysis have been done on three welded joints.Some results have been obtained below.In the given welding parameters,the welded joints show good tensile and forming properties.However,it has been also found that the cracking is easy to occur in the fusion zone of welded joint during deformation.Some research works have been done.The results show that the fast cooling of fusional metal leads to the phosphorus microsegregation in the fusion zone because of relative low diffusion rate of phosphorus,which brings about the poor toughness of welded joints.
文摘Since it has excellent tensile strength, the quenching and partitioning （Q ＆ P） treated steel has been widely acclaimed. Some researched is currently being conducted on Q ＆ P steel, but Q ＆ P techniques and related mechanisms have been mostly research based on conventional transformation-induced plasticity （TRIP） steel. This study researches the effect of Mn on the properties of Q ＆P sheet steel. Two kinds of steel sheet with different levels of Mn content （1.46% Mn and 2.75% Mn） are investigated. After being fully annealed, the steel sheets were quenched to a temperature between Ms and Mr. Allocation treatment then caused the carbon to be partitioned into the remaining austenite.The microstructure and tensile properties were analyzed. The results show that the increment of Mn content can increase the stability of the steel and decrease the sensitivity of the quenching temperature （QT）. The results also indicate that increasing the level of Mn can effectively suppress the formation of bainite.
文摘对试验用淬火配分(Quenching and Partitioning,Q&P)钢在一步淬火配分工艺中不同淬火温度(220、260、300℃)和淬火时间(60、120、180 s)下组织、织构、力学性能及拉伸断口特征进行研究.结果表明:试验用Q&P钢在一步淬火配分中获得的最大残余奥氏体体积分数为7.12%;随着淬火温度升高,板条马氏体的宽度增大;随着淬火温度和配分时间升高,织构的最大强度逐渐降低,抗拉强度逐渐减少;屈服强度和延伸率呈相反的变化趋势.
