Deposit formation on chromium-plated cylinder liner in a fully formulated oil

Abstract

Chromium plated cylinder has been wildly used in large bore diesel engines due to its light weight, good durability, and low induced liner wear. Deposits accumulated in the grooves and micro-crack on chromium plated cylinder could smooth the running surface, reduce the oil retention capability, and increase the engine’s oil consumption. In the present research, deposit formation on chromium-plated cylinder in fully formulated oil under different loads and temperatures was investigated by using a reciprocating sliding tester. Surface analytical techniques such as SEM, EDX, and XPS have been used to gain the knowledge about deposits’ origin, distribution, and factors affecting the deposit formation. The deposits are mainly derived from C, O, and S in the lubricating oil and anti-wear additive ZDDP (Zn and P). Deposits only accumulated in the depression (honing grooves and micro-cracks) on chromium plated cylinder surface, and there were no deposits found on the plateaus. The deposit formation increased with the increasing of load and temperature, and increased sharply over 60 MPa and 150℃. The deposit formation on liner surface was significantly different between chromium-plated coating and cast iron in component and distribution.