The screw and barrel of extruder are made of high quality 38crmoala allay steel , the hardness is over hv950 after nitrogenizing treatment 再生料粉料或颗粒料拉制扁丝。挤出机的螺杆机筒采用
2.
It was suggested that the urban sewage of shanghai city be de - nitrogenized and de - phosphorusized before releasing in order to control the occurrence of red tide ?控制赤潮的发生，建议上海城市污水排放前进行脱氮除磷处理。
