"hardly achieved" is correct and usable in written English.
You can use it to talk about something that was difficult to do and difficult to attain. For example: "Winning the championship was a goal we had hardly achieved."
Women have hardly achieved parity with men in the industry, of course.
And an economy that's growing, but has hardly achieved liftoff, remains a soft spot for the Democrats.
A high quality joint of zinc based pressure die cast alloys can be hardly achieved by conventional fusion welding.
The evaluation of such policies requires a reliable identification procedure that is hardly achieved in empirical studies.
Legal proceedings against former communist politicians (few of which ended with convictions) hardly achieved the desired function of clearing up and catharsis.
We show that consensus networks over finite fields converge in finite time, a feature that can be hardly achieved over the field of real numbers.
You will hardly achieve a Vienna quality of handshake on email and Skype.
However, the existing optimization methods for SO2 conversion rate can hardly achieve the optimal effect, because the parameters change and the working conditions fluctuate during the production process.
But whereas the available machine tools hardly achieve the required process dynamic and accuracy in all degrees of freedom, the requirements still increase.
Traditional adaptive dynamic programming (ADP) is a suitable tool to address the problem but training usually suffers from low convergence rates and hardly achieves an effective controller.
However, conventional airborne and spaceborne SAR can hardly achieve them simultaneously.
