Polish troops armed with submachine guns and led by several tanks stormed the Lenin Steel Works early Wednesday, badly beating some strikers and threatening to shoot those who did not return to work, according to strikers who were there.

The steel works, which employ almost 40,000 people and are the largest production facility in Poland, were partly back in operation Wednesday afternoon.

About 75 soldiers, backed by many others in trucks and out of sight, guarded the front gates of the steel works from an angry, jeering crowd of several hundred.

Workers went on strike and began occupying the steel works Sunday evening to protest the declaration of martial law and a ban on union activity.

The embattled government of Gen. Wojciech Jaruzelski appeared to be trying to fortify its position by showing that it will enforce martial law in restoring production to an economy teetering near collapse.

The government also used troops to end a strike in Szczecin, and in Krakow some strikes collapsed after officials warned that strikers would never be rehired for the same work.

But the overall feeling seemed to be that the government was losing ground. Strikes continued at most large factories in Krakow and reports from other cities -- reports which came mostly from the Solidarity independent trade union and could not be confirmed -- indicated that strikes were widespread throughout the country.

At the Lenin Steel Works, eyewitnesses said soldiers severely beat students and strikers who resisted when troops broke down the gates and entered. Those beaten as well as strike leaders reportedly were taken to a prison.

Strikers were told that they had been mobilized into the Army and would have to work under military command. If they did not work, they were told, they could be imprisoned or shot.

Workers interviewed as they left the steel works were clearly alarmed and predicted that most strikers would return to work, but would perform their jobs slowly and poorly.

Witnesses said regular Army troops did not participate in the storming of the steel works, although they were present. The troops actually leading the way were said to be members of a special tactical force known as ZOMO, which is looked upon with disdain in comparison with regular Army units.

Some Army officers reportedly refused to participate in the attack on the strikers at the steel works and those in the crowd outside the gates said of the Army, "They're with us." On Wednesday afternoon, the crowd angrily confronted the militiamen and taunted them with chants of "You're not going to win." The crowd also yelled out greetings in Russian, implying that the militia were Soviet pawns rather than true Poles.

Officers in sound trucks ordered the crowd back and there was no violence. A protest march, illegal under the current martial law, was planned for the same area on Thursday afternoon.

Solidarity organizers and other dissidents were believed to be held in a prison Bialoleka near Warsaw.

Because of the dearth of official information and the lack of effective communication, Poland has become a gigantic rumor mill. Stories pass from person to person, often changing as they go. For example, some people outside the steel works insisted that the snow inside the gates was stained with blood and that bodies still lay on the ground. Strikers coming out, and those who were there, denied anyone had been killed and said there was little, if any, blood on the snow.

In Katowice, about 40 miles northwest of Krakow, a strike at the steel plant is said to be continuing. A Western source in Krakow said the president of Silesian University in Katowice and some professors have been arrested for criticizing the imposition of martial law.

Most Poles refuse to speculate on how the current crisis will end. They admit the possibility of Soviet, Czechoslovak or East German invasion, of victory by Solidarity or of some compromise between the government and Solidarity that would end martial law.