The House yesterday gave President Carter an important victory in his foreign policy toward Africa by voting him power to cut off U.S. imports of Rhodesian chrome.

By a vote of 250 to 146, the House voted to permit the President to put the United States back in compliance with economic sanctions against the white minority regime in Rhodesia voted by the United Nations in 1968. The United States supported the sanctions vote in 1966, but abandoned them by a vote of Congress in 1971.

The Senate yesterday rejected by wide margins three weakening amendments on the same bill, and is expected to pass it today.

The Carter administration strongly supported the reinstatement of the ban as a method of underscoring U.S. commitment to black majority rule in Africa. U.N. Ambassador Andrew Young was on hand to observe the House proceedings.

Administration officials and the bill's supporters have maintained that the importing of Rhodesian chrome - which in 1975, the last year for which official figures are available, totaled roughly 220,000 tons worth more than $45 million - was no longer necessary. They said the United States has a more-than-sufficient stockpile of chrome for strategic purposes.

Carter had pressed for congressional action now so that when he addresses the U.N. General Assembly on Thursday he can deliver the message that Congress had put the United States in compliance.

The 1971 amendment that abandoned the U.N. sanctions was authored by Sen. Harry F. Bryd Jr., (Ind-Va.). it permitted resumption of Rhodesian chrome imports and was argued at-the-time on economic grounds that the United States, which mines no chrome, should not be made to depend largely on the Soviet Union for chrome, which was essential for the production of stainless steel. Aside from Rhodesia, the Soviet Union, South Africa and Turkey supply the bulk of chrome to the United States.

Yesterday's House vote overriding the Bryd amendment was urged as a vote for human rights in Africa, and made easier by the fact that the United States steel industry also says it no longer needs Rhodesian chrome.

Rep. John Buchanan (R-Ala.), a strong supporter of the bill, told the House: "Every African nation looks to us today." The vote, he said, was "for or against black rights on the continent of Africa."

Rep. Donald Fraser (D-Minn.), manager of the bill, said the regime of Ian Smith, which represents only the 5 per cent of Rhodesia that is white, will not remain in power more than a few months and that the United States should show where its sympathies lie before the black majority takes over.

Rep. John Dnet (D-Pa.), who had long supported the Bryd amendment because of the needs of steel companies in his district, charged positions because he said technological advances have made Rhodesian chrome no longer essential.

Asked why he favored an embargo on Rhodesia chrome while permitting imports from the Soviet Union and South Africa which are not noted for championing human rights, Dent replied: "My position is based on need, not human rights."

Opponents argued that a cutoff of Rhodesian chrome would raise the price this nation must pay other suppliers or would make the United States dependent for future supplies on uncertain sources. The United States has enough chrome in its strategic stockpiles to fight a war lasting several years, supporters of the bill said.

An attempt by Rep. Robert E. Bauman (R-Md.) to cut off chrome imports from any nation unless the President certifies it to be in compliance with U.N. charter provisions on human rights was rejected by the House, 246 to 153. Fraser said this would kill the bill because the President could not certify that any nation mining chrome is in compliance.