The quick answer is NO.<br>
A detailed answer: On this official [documentation][1], you can read: 

> When only the key is specified using the -K option, the IV must
> explicitly be defined. When a password is being specified using one of
> the other options, the IV is generated from this password.

**IV** stands for Initialization Vector. You can understand quickly how it is used with the combination of the key on this [figure.][2]


  [1]: https://www.openssl.org/docs/apps/enc.html
  [2]: http://en.wikipedia.org/wiki/Cipher-block_chaining#Cipher-block_chaining_.28CBC.29