紧固件用SA-540合金钢的强韧化工艺研究

通过成分优化(/%:0.35～0.46C,0.6～1.0Cr, 1.50～2.05Ni, 0.18～0.32Mo, 0.1V)、冶炼工艺(3 t VIM+ESR)以及热处理工艺(再次热处理工艺：850℃2 h水冷+590℃5 h水冷)的合理制定,获得了满足指标要求的紧固件用高强高韧SA-540合金钢材料。结果表明,为确保SA-540合金钢高温300℃规定塑性延伸强度R_p0.2≥860 MPa,室温抗拉强度应控制在1150～1170 MPa,仅有20 MPa的强度范围。对于经850℃2 h淬火/水冷+560℃5 h回火/水冷调质处理后室温抗拉强度超标的紧固件,可再次通过重新淬火并提高回火热处理温度(850℃2 h淬火/水冷+590℃5 h回火/水冷)使合金钢拉伸性能满足指标要求。SA-540合金钢淬火后随回火的温度升高,呈现抗拉强度和屈服强度下降、伸长率和断面收缩率增加的变化趋势。添加0.1%V的SA-540合金钢,可明显提高合金钢的强度和塑性指标,但低温冲击性能降低明显。     

A novel rhodamine-based fluorescent and colorimetric “off-on” chemosensor and investigation of the recognizing behavior towards Fe

A novel rhodamine based probe has been synthesized as an “off-on” chemosensor for Fe³⁺. Upon coordination with Fe³⁺, the probe displayed good brightness and fluorescent enhancement. A linear relationship was observed to exist between the relative fluorescence intensity of this probe and the concentration of Fe³⁺ in the range of 5 μM-20 μM with a detection limit of 5 μM. It offered highly sensitive toward Fe³⁺ over other ions. The recognizing behaviors toward Fe³⁺ have been investigated both experimentally and computationally. It can be expected that Fe³⁺ coordinated with the N atom of thiazole moiety in the probe accompanied by the transferring of electrons of the phenylthiazole resulted in the opening of the spiro-ring.     

球磨分级自动化控制系统

球磨分级是选矿工艺流程中能耗最高的环节,仅球磨机的能耗几乎占整个选矿场能耗的1／3,而整个球磨分级要占整个能耗的一半,并且其随机干扰因素众多,各工艺参数之间的相关性很强,一个参数的变化会引起多个参数乃至整个过程发生变化。人工操作不易及时和准确地判断与调整各操作参数,加之工人经验和责任心不同,就更难保障各工艺参数稳定处于最佳值。