\documentclass[a4paper,10pt]{article}

\makeatletter
\let\ps@plainOld\ps@plain
\def\ps@plain{}
\makeatother

\title{Titel}
\pagestyle{empty}
\begin{document}
\maketitle

\section{blah}
blub
\clearpage
\section{blah}
blub
\clearpage
\section{blah}
\pagestyle{plainOld}
blub
\clearpage
\section{blah}

\end{document} 
