求翻译：机身采用三梁四柱式结构，立柱采用超压预紧，刚性好；油缸柱塞采用优质碳素结构钢锻件，柱塞表面经中频淬火处理（淬火硬度不低于不小于HRC40-42），确保油缸的活塞杆耐磨、美观、耐腐蚀是什么意思？

Three beam four-post structure of the fuselage, the column overpressure pretension, good rigidity and high-quality carbon structural steel forgings; fuel tank plunger, the plunger surface IF quenching (quenching hardness of not less than not less than hrc40-42) to ensure that the fuel tank of the pi

The body frame 4 with a 3 column, the column structure with the ultra-pressure pre-tight, rigid; cylinder plunger with high quality carbon steel forgings, plunger surface hardened with the MF (hardened hardness is not less than 40 - are not less than 42 HRC), make sure the cylinder rod wear, beautif

The fuselage uses three Liang tetrastyle structure, the column uses the overpressure pre-tightly, the rigidity is good; The cylinder plunger uses the high quality carbon structural steel forging, the plunger surface (quenching degree of hardness is not lower than after intermediate frequency quenchi

Machine body adopts three Liang Sizhu structure, columns used ultra compression preload, good rigidity; oil cylinder piston made of high quality carbon structural steel forgings, piston surfaces by medium frequency induction hardening treatment (quenching hardness no less than of not less than HRC40

正在翻译，请等待...