Two Republican congressmen used harsh words yesterday to denounce Gen. George Brown, chairman of the Joint Chiefs of Staff, for supporting President Carter's plan to withdraw U.S. ground troops from South Korea.

"I think (Brown) has placed the expediency of staying around for another couple of years over what his personal integrity is," said Rep. Robin L. Beard (R-Tenn.)

Rep. Robert Badham (R-Calif) implied that Brown had been forced to support the decision.

Badham said Brown backed Carter's decision after he got additional information was that he may not keep his uniform," the congressman charged.

They made the comments at a hearing on Carter's U.S. troop withdrawal plan by the House armed services investigations subcommittee. Most sub-committee members oppose Carter's withdrawal decision.

Rep. Samuel S. Stratton (D-N.Y.), the chairman, has said he is looking for a way for Congress to modify the authorize Carter to turn U.S. equipment over to South Korea as the troops leave, he said.

Retired Gen. Richard G. Stillwell, who was U.S. commander in South Korea until last year, testified that no more American units should be pulled out without concessions from North Korea.

He charged that a U.S. pullout carries a risk of war, which he said could not be confined to the Korean peninsula because the Soviet Union and China would come to North Korea's aid.

Stillwell said South Korea could build its own defense in 15 years, but he added that this would risk an arms race including acquisition of nuclear decision. The vehicle may be a proposed bill by which Congress would weapons by the two Koreas.

"There is no way you could isolate a war on that peninsula," Stillwell testified. "A war in Korea is a no-win scenario."

He said, "Any further (U.S.) withdrawal should be conditional on countervailing moves by the Communist groups . . . to reduce tension."

The U.S. pullout should be used as a bargaining tool to gain permanent boundaries for North and South Korea, admission of both to the United Nations and "some sort of modus vivendi" for coexisting side by side, Stillwell said.