Performance of various pickling solution for rusty mild steel

Ed. note: Hundreds of people have read your request but no one has chosen to respond, Jone. You might want to look at the nature of your question--perhaps those readers think that you should go to a library for research of that type.

A. As my supervisor constantly tells me that research is search, re-search and re-search.
Ted was kind. You are literally asking people to do the bulk of the library work for you. That is what books are for. A paper with "comments" from unknowns would be laughed out of class. You need citations from verifiable sources.
Now then, there is rust, blush rust, deep rust, really deep rust and etc. You need to quantify what you are trying to do. Is there mill scale? are there other soils to contend with. What is the size, surface finish and cleanliness of the sample now and what is the final results required? The list of needed information goes on and on, and yes, it does make a big difference.
A pickled surface is very active and will re rust rapidly, sometimes before you can blow a large part dry.
Sorry,

A. Various chemicals of differing concentrations will remove rust from mild steel. HCl @room temperature and 25% conc. H2SO4 @ 50 °C and 15% conc.Both for 10 - 15 mins. There are alkaline solutions which will achieve a similar effect. NaOH @ 50 °C and 120 g/l. There are numerous other chemicals, times, concentrations which need to be considered.
As mentioned by other contributors the information you are asking for is readily available and and if you're as persistent in your library research as you are in this forum you should find all the information you require relatively quickly.

A. What do you think will work? What have you tried?

We get very good results using a commercial alkaline deruster, which operates at 180 °F. I neither know nor care about the exact chemistry, as the company I buy it from makes the formulation and considers it proprietary.