Senate Republicans, steaming over President Reagan's about-face on freezing Social Security benefits, complained yesterday that he had abandoned a major weapon in the fight against soaring budget deficits without demanding anything in return.

The criticism was especially strong from many of the 22 Republicans who are up for reelection next year and fear that Democrats will exploit their support for a Social Security freeze, especially now that Reagan has abandoned their cause.

"People feel they flew a kamikaze mission and ended up in flames and got nothing for it," Sen. Warren B. Rudman (R-N.H.) said after a closed-door session in which many of the 22 vented their anger to GOP leaders and White House officials.

"If the president can't support us," added Sen. Charles E. Grassley (R-Iowa), "he ought to keep his mouth shut." Grassley said "it would be better if the president sticks behind us rather than Tip O'Neill."

At a meeting of the Senate Finance Committee on the president's tax overhaul bill, Chairman Bob Packwood (R-Ore.) said he did not know if he could support the budget compromise. "There is little worse in government than misleading people," Packwood said. And Sen. John C. Danforth (R-Mo.) wondered aloud whether Congress should attempt tax reform if it can't cut deficits.

"A lot of senators are pretty upset about what they perceive to be a House-White House combine," said Majority Leader Robert J. Dole (R-Kan.).

"There's a lot of negative comment among senators about what happened, with a great deal of justification, that's for sure," said Budget Committee Chairman Pete V. Domenici (R-N.M.).

The rebellion within Senate GOP ranks cast new doubt over whether House-Senate budget negotiators, who met separately yesterday without any attempt to meet face-to-face, can reach a final compromise.

Under an agreement between Reagan and congressional leaders earlier this week, they are attempting to write a deficit-reduction plan that provides inflation-covering increases for both defense and Social Security, without any tax increases.

Senate negotiators are demanding equivalent cuts in other domestic programs to offset the loss of savings from Social Security; House bargainers say they will propose additional cuts but are resisting the demand for equivalent savings, which would amount to about $28 billion over three years.

Domenici said there is "very little chance" the Senate would support anything less than $28 billion. House Majority Leader James C. Wright Jr. (D-Tex.) said such a figure is "sheer fantasy."

In terms of first-year savings, Domenici called for $6 billion to $8 billion. House Budget Committee Chairman William H. Gray III (D-Pa.) said $3 billion to $6 billion is possible and called on subcommittee chairmen to find "the maximum amount of cuts."

But Gray also insisted that it is the responsibility of the Senate, not the House, to meet any Senate demands. "He [Domenici] says we've got to cut $28 billion. I say, who is we, Kemo Sabe?" Gray said.

Some of yesterday's angst among Senate Republicans stemmed from a statement by presidential spokesman Larry Speakes that Reagan had always opposed tampering with Social Security and had supported the freeze "reluctantly" as "the only way to put the package together" in the Senate. "There was concern that that compounds the problem," Domenici said.

But some senators agreed that Reagan was only a reluctant convert to the Senate's position. "The president was never really with us on Social Security; we got out there on our own," Packwood observed.

As Congress wrestled inconclusively with spending cuts to keep deficits under $200 billion for the rest of the decade, the Senate Judiciary Committee approved two alternative constitutional amendments to require a balanced budget, one of which would also limit tax increases to annual increases in national income. They will reach the full Senate after Labor Day.

Deputy Treasury Secretary Richard G. Darman said yesterday that overhauling the tax code should not be put on hold until Congress and the White House achieve deficit reductions.