Workers at the Eastern Stainless Steel plant just outside of Baltimore got an unseasonal jolt yesterday when Eastmet Corp. announced that 450 of its employes at the plant would be laid off Sunday, three days before Christmas.

"I feel sorry for the people with families and kids who believe in Christmas," said Jim Kyle, a 54-year-old plant electrician who said he does not yet know whether he will be among those laid off. Kyle and several co-workers who gathered at Ruggieros bar near the plant after their shift ended yesterday said they did not expect to learn who would be laid off until today, when next week's schedules are posted.

The work force is in "confusion, utter confusion, because nobody knows what's going on," said Kyle.

Eastmet, which has been forced to the brink of insolvency in recent years by the high costs of production and soft demand for American steel, said the layoffs were an effort to scale back operations and cut costs. The cuts will leave 500 people employed at the plant.

William F. Dausch, Eastmet's president, said in a statement that the company "deeply regrets this action but believes it is required in order to provide the company the opportunity to return to profitability."

The cuts were especially bitter for workers at the plant because, in an effort to bolster the ailing firm, they accepted a $4.50 an hour reduction in wages last year.

David Wilson, district director in Baltimore for the Steel Workers of America, the union representing many of the Eastmet workers, said grimly, "Even if we worked for nothing, it wouldn't matter."

"There's just a feeling of total frustration," he added. "The problem, as I see it, is that people in Washington don't understand what is happening in the country or just don't give a damn."

That frustration showed through at Ruggieros yesterday. Edward Morris, 50, a switchman who has been with the company for 33 years, said he was upset that the employes learned of the planned layoffs through news reports.

"I think the company should have notified the unions to let the men know ahead of time," he said.

Jim Chmielewski, a 51-year-old millwright, said many of the younger workers who are likely to be laid off "are bitter to say the least. They've made commitments that they're not going to be able to meet by the company doing what it's doing."

Chmielewski, who lives in Dundalk with his wife and 17-year-old son, also said he does not expect to be cut from the work force. But he and other Eastmet workers said they are concerned about the company's prospects for long-term survival.

Eastmet President Dausch said that the company had hoped that an agreement with its lenders would have allowed "the survival of the entire operations of the company." But he added that the "inability of the company to maintain certain price increases and other factors made it clear in recent weeks that the plan . . . would not be achieved."

A company spokesman said Eastmet losses were running at $14.5 million through the first nine months of the year, compared with losses of $5.1 million for the same period in 1984.

And the workers feared that the layoffs were another sign of a growing exodus of manufacturers from Baltimore and especially from its industrial area of Sparrows Point.

"All these industries are leaving this town -- Western Electric, Esskay, Black and Decker, the Point's down to nothing," said Chmielewski. He said he faults the Reagan administration for failing to restrict foreign imports. "This country is turning into scrooges," he said.