Characterize of Corrosion Rate and Mechanical Properties of Low Carbon Steel in Potassium Chromate Solution

Corrosion is one of the degradation materials in Industrial problem. One of the processing to choose material is to determine how to have resistance to all the environment. This research is carried out to determine characterize the effect of various temperatures (150, 200, 250 °C) and time (4,6 and 8 hours) of exposure of Low Carbon Steel in corrosion rate and mechanical properties by using Mass Balance method and Potassium Chromate vapor as medium corrosion. The results have been shown that the increasing temperature ids increasing corrosion rate which is the maximum value is 5,1215 x 10−4 miles/years. The difference in corrosion rate increasing by 6,3 % based on increasing temperature. The microstructure has shown is intergranular corrosion mode.


Introduction
In everyday life, we easily encounter corrosion and occur in various types' metal. Electronic equipment and building material are metal components such as copper, zinc, steel and others that can be attacked by corrosion. In addition to large metals, corrosion can also attack metals on electronic equipment components, ranging from computer components, watches and equipment used in the lives of humanity, both in domestic life and in industrial activities Corrosion is very common in iron. Iron is a metal that is susceptible to corrosion if a protective coating is not provided. Rust in iron is a substance that is produced in the event of corrosion that is, in the form of a reddish brown solid which is fragile and porous. Corrosion process occurs in almost all metal materials that occur slowly, corrosion results in a material having a limited life, where the material is expected to be used for a long time turns out to make a shorter life span than the average usage life. Corrosion prevention can be done in various ways, one example is cathodic protection, by providing a coating on a metal surface, and adding 3 corrosion inhibitors. The addition of corrosion inhibitors is one of the most effective ways to prevent corrosion because it requires a relatively low cost and simple process. Corrosion events are very detrimental to industry and society. One example of the phenomenon of the effects of corrosion is a broken bridge due to the metal parts affected by corrosion. The metal part of the bridge which is affected by corrosion will reduce the strength of the bridge construction

Method and Materials
Carbon steel is an alloy between iron (Fe) with carbon content between 0.10% -0.14% C. Based on the amount of carbon content, carbon steel can be clarified into 3 types. The material was used Carbon Steel S45C 2.1 Strain Gauge A strain gauge is a metal or semiconductor element whose resistance changes when under pressure [2]. A strain gauge consists of three core parts, namely: wire, base, and adhesive. Because all materials are resistant to deformation, several forces must be applied to cause a deformation. Then, resistance can be related to the force applied. The number of strain gauges applied at high temperatures using platinum metal groups has been developed. Platinum, a metallic metal used in strain gauge has a composition in percent by weight: platinum (8.5 ~ 9.5) tungsten (Pt-(8.5 ~ 9.5) W) (1), platinum-8 nickel-2 tungsten (Pt-8Ni-2W), platinum-8 nickel-2 chromium (Pt-8 Ni-2 Cr) (2), and palladium -13 Chrome (Pd-13 Cr) (3). Strain gauges containing non-precious metals are: Copper-Nickel (Cu-Ni), Nickel = Chrome (Ni-Cr), and Iron-Chrome-Aluminum (FeCr-Al) [3].

Figure 1. Strain Gauge
Corrosion is metal degradation or damage caused by a redox reaction between a metal and various substances in the surrounding environment that produce unnecessary compounds. In everyday language, corrosion is called rusting. The most common example of corrosion is iron rusting [14]. In the event of corrosion, the metal undergoes oxidation, while oxygen (air) has a reduction. Metal rust is generally in the form of oxide or carbonate. The chemical formula for iron rust is Fe2O3.nH2O, a red-brown solid.The average static corrosion rate at high temperatures is indicated by the change in mass per unit area expressed in The test materails were used:

Results and Discussions
Retrieval of test data is carried out to determine the change in output voltage (Vout) on a digital multimeter due to chemical reactions (oxidation) between the element Fe with the element K₂ CrO4. The data is obtained by recording a multimeter and digital multitester display for 1 minute per hour during the test time conditions (4, 6, 8 hours). To obtain accurate data, 12 data are taken in 1 minute, meaning that data is taken every 5 seconds in 1 minute Chemical reactions that occur in this study K2CrO4 + 3O2 + 2Fe = CrO2 + 2KO + 2Fe (O) 3.
On the results of the study in       Vickers hardness test results on S 45 C steel obtained using the Micro Hardness Test LARYEE. In this hardness test, the hardness value of specimen 0 to specimen 9 is obtained, the value of hardness does not increase constantly because homogenization has not been done before.