Unless the American steel industry can be revitalized during the 1980s, the United States by the end of the decade will become as dependent on foreign steel as the nation now is on foreign oil, warns Bethlehem Steel Vice Chairman Richard F. Schubert.

Foreign steel producers -- namely the Japanese and Europeans -- then might form an OPEC-like cartel to boost prices, Schubert said last week at a seminar for 100 educators from area universitites' business schools.

Schubert, who also heads the Reagan transition team for the Labor Department and who has been mentioned as a possible secretary of Labor, said that without government relief for the ailing steel industry, the competitive position of American steel producers will continue to erode, leading to more plant shutdowns and job layoffs in both steel and related industries.

The Bethlehem steel executive, who served as solicitor of the Labor Department from 1971 to 1973, outlined President-elect Ronald Reagan's steel industry revitalization plan. It calls for faster depreciation allowances, stronger enforecement of antidumping laws, relaxation of air pollution and other federal controls, and other incentives to profitability.

The program also included a three-hour tour of Bethlehem Steels Sparrows Point plant, one of the world's largest steel mills.

"We have a depressed situation here," plant general manager Russell Jones said. "For the past six months, we have had anywhere from 3,000 to 4,000 people on layoff and I don't see any major increase in our operations over the next six months or so." The plant normally emplpoyes 18,500.

Jones expressed optimism that the steel industry could be revitalized but said the industry couldn't do the job alone. Revitalization will require the help of everybody, including the government, he said.

The Bethlehem manager strongly denied that his company was seeking a federal handout, however. "All we are asking is that the federal government enforce the trade laws that are on the books and prevent the dumping of foreign steel in the United States that takes away jobs from our people in this community," he said.