Shyam Lal (35) and Bajrang (25) died on the spot in Dariba plant of the company here, police said.
Injured were rushed to a hospital, where the condition of one of the workers was stated to be critical.
The accident took place at about 2 pm when the workers were cleaning the boiler, company sources said.
The material in the boiler was hot at about 300 degree Celsius and it spilled over them.
Most of the workers were on contract basis and were employed by a private SS company.