Welding technology of 45 steel and 35 CrMo cast steel

Abstract

The invention discloses a welding technology of 45 steel and 35 CrMo cast steel. The technology includes the following steps that firstly, preheating is performed, a plate core and a plate piece are placed into an annealing furnace for being preheated to the temperature of 300 DEG C at the temperature rising speed of 40-60 DEG C per hour, heat preservation is performed for one hour, the plate core and the plate piece are taken out of the furnace and assembled, gas is used for continuous heating, and therefore the welding process is constantly kept at the preheating temperature of 200 DEG C and 250 DEG C; secondly, according to a welding manner, an H08Mn2SiA welding wire is adopted, and the argon-rich CO2 gas of 80% of Ar+20% of CO2 is used for protecting welding; thirdly, according to welding parameters, the diameter of the welding wire is 1.2mm, the welding currents are 190-240A, the welding voltage is 28-32V, the interlayer temperature is 200-250 DEG C, and the gas flow is 15-20L / min. Multilayer and multi-bead welding is adopted, welding beads are mutually overlapped, and the width of an overlapped welding joint is no smaller than 1 / 3 that of a welding joint. Meanwhile, each time one layer is welded, an air chipper is used for hammering the welding joint to relieve stress, and after welding, stress relief heat treatment is performed in the furnace. According to the welding technology of the 45 steel and the 35 CrMo cast steel, restraint stress can be greatly reduced, and therefore cracks are effectively prevented.

Description

technical field [0001] The invention relates to the field of welding of different steel materials, in particular to a welding process of 45 steel and 35CrMo cast steel. Background technique [0002] The hammer crusher is a machine in which the motor drives the main shaft, discs, pins and hammers to rotate at high speed. The hammers are installed on the pins between the discs in the form of hinges. withstand pulsating shock loads. It is made of a 35 CrMo disk core and 10 pieces of 45 steel plate discs. The thickness of the disc is 80mm. The boss at the welding place between the core and the disc is 80 mm. And large, the structure is very rigid. After welding, due to the shrinkage of the weld seam, a large restraint tensile stress is generated, which is easy to cause cracks. Therefore, the size of the weld seam should be reduced as much as possible to reduce the stress. Since the distance between the discs is only 178mm, the first piece of welding between the disc and the di...

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Problems solved by technology

[0003] 35 CrMo steel has a considerable hardening tendency, and the quenched structure after welding is brittle and hard high-carbon martensite, which is highly sensitive to cold cracks. In addition, the thickness of the disk and the core boss are both 80 mm, and the constraint degree Larger, prone to larger restraint stress, which is likely to cause embrittlement or cracking in the weld-affected zone

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