There a number of things that could be going wrong here. The first is the SD card is bad and that's why its corrupted or you might not have properly imaged the SD card.
Its not entirely clear what OS you are using but here are the steps if you have a windows computer. If you are using Linux a similar process applies:
First you are going to need to format the SD card, for Windows a piece software called MiniTool Partition Wizard exists. This allows you to see the different partitions on the SD card. Delete any partitions on the SD card and create one primary active partition the size of the SD card. Then in File Explorer right click on the SD card select format and format it to device defaults. Now your SD card is good to go for the installation.
Then go to the official download page for Raspbian.
Click the Download ZIP button, the ZIP file will start to download.
Once the download has completed you will need to unzip the 2017-04-10-raspbian-jessie.zip folder. Inside the unzipped folder you will find a Disc Image File called 2017-04-10-raspbian-jessie.
This file is what gets written to your SD card. to write the Disc Image File to your SD card is going to require a program like Win32 Disk Imager. Once you have it installed, open it and you will see a window like this:
Click the little folder button and go to the file location of the un-zipped Raspbian Disc Image file and select the file. You will also need an SD card connected to your computer and the location of that can be set under the Device drop down menu.
Once you are happy that you have the Disc Image File and correct drive letter for the SD card selected you can press the write button. It will take a few minutes for Raspbian to be written to the SD card. Once a message pops up saying the write was successful you can safely remove the SD card from your computer.
The SD card is now ready to be used in a Raspberry Pi. A slightly easier method of installation is to use NOOBS, which can be downloaded here. Once you have downloaded the ZIP file it will need to be unzipped. Once unzipped the files in the unzipped folder need to be copied to the SD card. And from there the SD card can be used in a Pi.
If after following these steps you are still encountering problems try using a different SD card. You also need to ensure you are powering the Pi adequately, be sure to use a power supply that can reliably provide 2A at 5V.