Konstantin Konstantinovich Khrenov (Russian: Константин Константинович Хренов; 13 February 1894 – 12 October 1984) was a Soviet engineer and inventor who in 1932 introduced underwater welding and cutting of metals.

[1][2] For this method, extensively used by the Soviet Navy during World War II, Khrenov was awarded the State Stalin Prize in 1946.

In 1918, he graduated from the department of electrochemistry of Saint Petersburg State Electrotechnical University (ETU).

[4][5] In this method, the gas bubbles formed as a result of welding reactions were generating a stable flow which shielded the arc from water.

[7][8] For his pioneering work in underwater welding, Khrenov was awarded the State Stalin Prize in 1946.