  By using post-annealing and quenching technique, we show that the critical
current density Jc,ab of KxFe2-ySe2 single crystals can be enhanced more than
one order of magnitude up to ~ 2.1 \times 10^4 A/cm^2 at 1.8 K. The scaling law
between normalized pinning force and reduced field for all measured
temperatures was observed, reflecting the presence of only one dominant pinning
mechanism. Analysis indicates presence of 3D point-like normal core pinning
sources in quenched KxFe2-ySe2 samples whereas dominant vortex interaction with
pinning centers is via spatial variations in Tc ("deltaTc pinning").
