The main characters in How Steel Was Tempered were Pavel Kochagin and Nikolay Ostrovsky. The relevant plot was as follows: The novel was first published in 1932 and tells the story of the protagonist, Pavel Kochagin, growing up during the Soviet Union's industrial era. He worked in a factory, experienced arduous labor and training, and gradually grew into a technical expert and leader. In addition, he also experienced various events during the Soviet revolution and war, including fighting with the enemy, political struggles, and natural disasters. The novel used Kochagin's growth as the main line, interweaving the stories and experiences of other characters to show the fate of the Soviet society and people. The novel was widely acclaimed as one of the greatest novels of the 20th century. The protagonist, Pavel Kochagin, was hailed as the "leader of the steel workers" and "hero of the era of socialism'. His image was widely praised and worshipped in the Soviet Union and around the world. In addition, the novel has been translated into many languages and has a wide readership around the world.