A high-building multi-directional pipe joint(HBMDPJ)was fabricated by wire and arc additive manufacturing using high-strength low-alloy(HSLA)steel.The microstructure characteristics and transformation were observed an...A high-building multi-directional pipe joint(HBMDPJ)was fabricated by wire and arc additive manufacturing using high-strength low-alloy(HSLA)steel.The microstructure characteristics and transformation were observed and analyzed.The results show that the forming part includes four regions.The solidification zone solidifies as typical columnar crystals from a molten pool.The complete austenitizing zone forms from the solidification zone heated to a temperature greater than 1100℃,and the typical columnar crystals in this zone are difficult to observe.The partial austenitizing zone forms from the completely austenite zone heated between Ac1(austenite transition temperature)and1100℃,which is mainly equiaxed grains.After several thermal cycles,the partial austenitizing zone transforms to the tempering zone,which consistes of fully equiaxed grains.From the solidification zone to the tempering zone,the average grain size decreases from 75 to20μm.The mechanical properties of HBMDPJ satisfies the requirement for the intended application.展开更多
中空注浆矿用锚索用6.20 mm 2200 MPa超高强度钢丝因强度要求高,生产难度大,在生产时容易出现断丝,表面处理时采用盐酸两道次浸泡酸洗,酸洗后水冲洗采用先高压水冲洗再浸泡洗然后再高压水冲洗的方式,水冲洗后选用锌系高温快速磷化液,磷...中空注浆矿用锚索用6.20 mm 2200 MPa超高强度钢丝因强度要求高,生产难度大,在生产时容易出现断丝,表面处理时采用盐酸两道次浸泡酸洗,酸洗后水冲洗采用先高压水冲洗再浸泡洗然后再高压水冲洗的方式,水冲洗后选用锌系高温快速磷化液,磷化时间3~5 min,选用8道次拉拔。采用该工艺生产的钢丝能够满足产品的要求。展开更多
基金financially supported by the National Key R&D Program of China(No.2017YFB1103200)the Independent Innovation Research Fund Project of Huazhong University of Science and Technology(No.2018KFYXMPT002)。
文摘A high-building multi-directional pipe joint(HBMDPJ)was fabricated by wire and arc additive manufacturing using high-strength low-alloy(HSLA)steel.The microstructure characteristics and transformation were observed and analyzed.The results show that the forming part includes four regions.The solidification zone solidifies as typical columnar crystals from a molten pool.The complete austenitizing zone forms from the solidification zone heated to a temperature greater than 1100℃,and the typical columnar crystals in this zone are difficult to observe.The partial austenitizing zone forms from the completely austenite zone heated between Ac1(austenite transition temperature)and1100℃,which is mainly equiaxed grains.After several thermal cycles,the partial austenitizing zone transforms to the tempering zone,which consistes of fully equiaxed grains.From the solidification zone to the tempering zone,the average grain size decreases from 75 to20μm.The mechanical properties of HBMDPJ satisfies the requirement for the intended application.
文摘中空注浆矿用锚索用6.20 mm 2200 MPa超高强度钢丝因强度要求高,生产难度大,在生产时容易出现断丝,表面处理时采用盐酸两道次浸泡酸洗,酸洗后水冲洗采用先高压水冲洗再浸泡洗然后再高压水冲洗的方式,水冲洗后选用锌系高温快速磷化液,磷化时间3~5 min,选用8道次拉拔。采用该工艺生产的钢丝能够满足产品的要求。
