The destruction of the environment is global. Every place and every person on the planet encounters various environmental problems, not only in terms of type and intensity, but also in factors such as natural causes or human induced factors. With the outstanding environmental problems, various activities have been carried out internationally, various treaties have been formulated, and various classification terms such as 'pollution crisis', 'energy crisis,' and 'water crisis' have emerged. In the case of water, it is rarely as humans hope. Either too much, too little, or too poor water quality. When a flood occurs in one place, the dry order may affect another district. Human beings live on the earth and inevitably bring changes to the surface water and land ecosystem. This kind of microclimate from urban to regional desertification; the water and land of industrialized countries are polluted by various channels, the social landscape is withered, the waste gas and waste water are affected by people's health; geological disasters occur frequently, many along the river and coastal cities Faced with the dangers of cyclical floods and slopes; earthquakes in various environments such as the Arctic, tropical regions, mountains, and plains all illustrate the universality of environmental problems. GCr15 52100 100Cr6 SUJ2 bearing steel bar GCr15 steel round bar,52100 steel round bar,100Cr6 steel round bar,SUJ2 steel round bar SHANDONG LE REN SPECIAL STEEL CO., LTD. , https://www.sdcolddrawnsteelbar.com