The steel industry was up in arms today over a familiar villian, the lower-priced imported steel that the industry claims robs jobs and profits and keeps U.S. producers from expanding.

But officials were armed with a new study which U.S. Steel Corp. chairman Edgar B. Speer said documents the long-standing claims by American industry that Japanese and European producers sell at below cost in the United States - except their own operating rates up and unemployment down.

Speer said the study documents "predatory pricing" by foreign steel makers that if committed by an American company would put somebody "in jail."

Speer, who is also chairman of the industry trade group, the American Iron and Steel Institute, said U.S. steel makers plan to use the study as the linchpin of a campaign to get the Carter administration to negotiate a worldwide steel agreement that would force foreign producers to sell in the United States at unsubsidized prices. He contended the industry is not looking for "protestion."

The study, commissioned by the steel institute, was made by the Newton, Mass., consulting firm of Putnam, Hayes & Bartlett, Inc.

"There is no question the study demonstrates that steel made in this country is made at lower costs than anywhere else in the world for the American Market," but the foreignmade steel here is "being shipped with some form of subsidy. In most instances - if not all instances - that is an incentive subsidy, "Speer said.

The Putnam, Hayes study, entitled the "Economics of International Steel Trade," argues:

Foreign steel producers are selling steel in the U.S. market at prices below their average costs, and this practice has been consistently used by foreign producers in the past whenever necessary to increase their capacity utilization.

Imports' share of the market is increasing and in the last months of 1976 was about 20 per cent of total U.S. steel consumptiion.

Prices are too low to induce either American or foreign producers to add substantially to current steel-making capacity (although there is now excess capacity of about 36 million tons).

Steel "demand will grow and . . . in the early 1980s the likehood of severe steel shortage in the U.S. will be present.

"Thus trade policies that allow imports to enter the U.S. market today at prices below full costs will foster shortages of a critical material for the American economy. This long-term viewpoint must be employed when anlyzing current trade issues," thw study contends.

Under questioning at a press conference, Speer would not specify the trade policies he would like to see the goverment adopt beyond a general statement that the steel industry should operate under the same rules in all countries.

"It's not a question of us going which the study predicts will recur down the tubes" but of whether the steel industry will be able to expand, to meet the domestic needs of the country. Speer said.

In a Keynote address to the annual convention of the American Iron and Steel Institute earlier, Speer charged that the "United States is now the only industrialized nation anywhere in the world that does not have the ability to produce all of its domestic steel needs at times of peak demand."

Foreign imports siphon the growing American demand for steel, undermining the profitability of American companies and preventing them from earning enough money to add needed capacity, he said.

During worldwide steel shortages - sometime in the mid-1980s - foreign suppliers become unreliable and expensive. The study points out that during a worldwide economic boom that boosted steel demand sharply in 1973 and 1974, foreign steel makers boosted their export prices substantially and cut back their shipments to the United States.

At some points in 1974, imported steel was selling for as much as $100 a ton more than American-made steel.

Speer said that there is no need for new United States laws to deal with the steel trade situation. "The laws on the books, if enforced or administered properly, are sufficient," he said at the news conference.

Under questioning, he said that the Carter administration has shown a "willingness to listen to our problems" and said that he has been encouraged that it "won't be business as usual. Something will happen."

But he said he had no idea what that "something" would be.

Speer reacted sharply to several questions during the 45-minute news conference. Asked whether the industry intends to develop a fair trade program and if so what it would include, Speer replied that he would rather take ideas to the government "than tell you . . . just like I would rather talk to my customers about the price of my products than tell you."

But Speer said that if a fair trade policy were established, a number of foreign producers - including presumably Japan and European nations - "would have to charge more than domestic producers."

He said the industry and the economy must grow. By 1985, there will be 20 million more people in the marketplace looking for jobs, Speer said. "What are we going to do? Drown every fourth person?" he asked.