The Newcastle player, 26, came off the bench in the last minute of extra time and saved two spot-kicks as his side won 4-3 on penalties.
Krul said he spoke to every Costa Rica player about to take a penalty to "try to get in their heads".
But he said: "I don't think I did anything wrong. I did nothing crazy. I didn't shout in an aggressive manner."
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He added: "I told them I knew where they were going because I had analysed it. It worked."
Netherlands manager Louis van Gaal said he substituted Jasper Cillessen with seconds of extra time remaining because of Krul's greater height and reach.
Cillessen, who kicked a water bottle as he came off, said: "I didn't know it was going to happen, so I was angry. I wanted to play the penalty shootout. It is a pity I wasn't told before, but it worked very well."
Ajax goalkeeper Cillessen, 25, is expected to start Wednesday's semi-final against Argentina, but Krul is drawing up a plan to deal with Lionel Messi and co if he is called into action again.
"We will analyse every Argentina penalty on Monday," added Krul. "We will sit together and write up a plan."
Dutch defender Ron Vlaar, who plays his club football for Aston Villa, is a doubt for the game because of a knee problem.
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Netherlands goalkeeper Tim Krul has defended his antics during the World Cup shootout victory over Costa Rica.