Corrosion is an electrochemical reaction between metals and the environment that causes corrosion and decreases the quality of metals. Steel is a metal material that is widely applied in the industrial world. Stainless steel is stainless steel that is resistant to corrosion because it has an alloying element of at least 18% chrome and 8% nickel. To find out the superiority of stainless steel as a construction material, research on local corrosion of stainless steel needs to be done. For this reason, research on corrosion is carried out by using a 10% NaCl salt solution by varying the immersion time of stainless steel in corrosive media. From the research results it is known that the type of corrosion that occurs in specimens is the type of uniform corrosion. Likewise with the value of violence will decrease if the stainless steel is soaked longer.

Energy storage such as vanadium redox flow batteries (VRFB) has increased to store renewable energy resources in the last decade. However, the unbalanced crossover level of vanadium is often a major constraint which has a significant impact on battery capacity and life cycle in long-term operation. Performing an asymmetric electrolyte volume is one of many ways to solve this problem. The different volumes on the positive and negative sides were analyzed to see their effect in suppressing the decrease in VRFB capacity. With the result of the optimal electrolyte excess ratio, long-term cycle performance was carried out to investigate the reduction in capacity of VRFBs.

An experiment has been conducted to determine corrosion rate of medium carbon stell with sulfuric acid solution, Aquades 90,2% + H2SO4 9,8% and hydrochloric acid solution, Aquades 96,8% + HCl 3,2%. By using weight loss method, if medium carbon steel dipped into sulfuric acid solution then the corrosion rate is faster than it dipped into hydrochloric solution. If medium carbon steel dipped in a long time than the corrosion rate slowing down.

Additive Manufacturing is the formalized term for what used to be called rapid prototyping and what is popularly called 3D Printing by adding layer-upon-layer of material, whether the material is plastic, metal,.etc. Stereolithography(STL) is the standard file type used by most additive manufacturing processes. This is the file type whichwill be saved from the 3D design software package, etc.solidwork.Most commonly the slicer and the client software are combined, making the conversion from STL file3D Print straight forward and simple. Before printing a 3D model from an STL file, it must first be examined forthe errors. The errors are surfaces or facets don’t meet and facets that are too thin. Software programs such as Meshmixer, Cura and Slic3r are examples, which will correct these issues.

This paper uses the Finite Element Method software to simulate the welding method, namely MSC Marc. The selected material is structural steel type C15 categorized as low carbon steel. The material has a thickness of 2 mm and butt-joint welding will be performed, which needs additional attention because welding is highly susceptible to distortion on thin plates. It can be seen that the simulation results against the sample SM 4PL Low have a lower temperature from the heat distribution data taken about 1 mm from the fusion line. Whether or not distortion happens on the plate is significantly affected. This information can be used to predict the real parameter of welding. However, it is better to ensure the best parameters; this data must be calibrated with the results of thermal distribution measurements through experimental methods.