In the hardening by welding process, customer needs are clear and focused, and our core task is to transform those needs into feasible and scalable solutions by leveraging the expertise and equipment advantages of welding cobots.
1. What are the core needs of customers?
Customers' demands for weld hardening processing focus on three key areas: substrate compatibility, layer thickness accuracy, and mass production. These can be broken down into the following three key areas, which also serve as the starting point for our solution design:
1．Substrate specifications: It needs to be compatible with 4mm and 6mm thick plates to ensure consistent welding hardening effect on substrates of different thicknesses and to ensure the bonding strength between the hardened layer and the substrate;
2．Layer thickness requirements: The thickness of the final weld hardened layer must accurately reach 3mm, and the surface must be flat, meeting the subsequent workpiece wear resistance, corrosion resistance and other performance standards;
3．Production requirements: Support multi-batch welding hardening production, requiring the hardened layer thickness, surface quality and performance parameters of each batch of workpieces to be highly consistent to avoid quality problems caused by batch differences.
Among them, welding hardening of 6mm plate is a typical scenario. Due to the physical properties of the welding process, such as molten pool flow and uneven heat input, the surface of the hardened layer after welding is inevitably uneven (local protrusions or depressions). How to find a balance between "reserved grinding allowance" and "the final 3mm hardened layer thickness" becomes the key to meeting the demand.
2. How ReadyOn Perfectly Solve the Problem
To address customer welding hardening needs, we use collaborative welding robots as the core. This systematic approach addresses these pain points through a "customized two-pass welding process (achieving a 4mm initial hardened layer)
→ standardized grinding (accurate to a 3mm target layer) → tooling + program reuse (ensuring batch consistency)" approach. The specific implementation steps are as follows:
a.How to achieve a 4mm initial hardened layer (allowing for a 3mm targ
For the welding hardening of 6mm plates, we adopted a two-pass welding process of "first pass circular oscillation + second pass flat welding". Through the precise control of the welding collaborative robot, a stable 4mm initial hardened layer was obtained, leaving sufficient space for subsequent grinding, while ensuring the metallurgical properties of the hardened layer.et)
First step: Circular oscillating welding – laying a uniform base layer
The welding collaborative robot first performs welding hardening in a circular oscillation mode: the preset oscillation diameter is 8-10mm (adapted to a 6mm plate width), and the single-pass penetration depth is controlled to approximately 1-1.5mm through dynamic current and voltage adjustment (pulse current 190-210A, voltage 22-24V), ensuring full fusion between the hardened layer and the substrate, with the initial bottom layer thickness stabilized at 2.2±0.1mm. The circular oscillation design increases the deposition range, avoids incomplete fusion defects at the plate edges, and reduces interlayer porosity, laying the foundation for the performance of the hardened layer.
Second step: Flat filler – stacked to a 4mm initial hardened layer
After the bottom layer welding hardening is completed, the robot switches to flat welding mode and uses a laser contour sensor to scan the surface morphology of the bottom layer in real time. If a local protrusion is detected, the welding speed is automatically increased to reduce the amount of molten metal deposited; if a local depression is found, the speed is slowed down and the filling amount is increased to ensure that the hardened layer thickness is uniform. At the same time, the overlap rate between the flat weld and the bottom layer is controlled at 50%-60% to further strengthen the interlayer bonding. Ultimately, the total thickness of the two weld layers is stabilized at 4±0.2mm, which leaves a margin of about 1mm for subsequent grinding, avoiding the hardened layer being too thin after grinding and affecting performance.
b. How to reduce thickness from 4mm to 3mm (eliminate unevenness and achieve precise molding)
Due to the physical characteristics of welding, the surface of the initial 4mm hardened layer will have unevenness within ±0.5mm. We use a "robotic-assisted grinding" method to precisely adjust the layer thickness to 3mm while ensuring the performance of the hardened layer.
After the welding collaborative robot completes the welding hardening, it automatically transfers the workpiece to the grinding station and synchronizes the three-dimensional contour information of the hardened layer (such as the position, height, and range of the recessed area) to the grinding equipment through data interaction, so as to avoid blindly grinding and damaging the structure of the hardened layer.
The grinding equipment uses a low-stress grinding process based on real-time data to specifically remove 0.5-1mm of excess material, ultimately obtaining a weld hardening layer with a smooth surface and a precise thickness of 3mm, and without significant loss in performance parameters such as hardness.
3. How to ensure consistency in multi-batch production
To address our customers' needs for high-volume weld hardening production, we employ a combination of "tooling fixture positioning + robot program reuse" to ensure that the weld hardening effect of each batch is consistent with the first piece, while simultaneously improving production efficiency.
Tooling and fixtures: Precise positioning reduces clamping errors
Custom-designed welding hardening fixtures are used for 4mm and 6mm plates respectively. Positioning pins and clamping devices secure the workpieces, ensuring a repeatability accuracy of ≤±0.1mm during welding and preventing uneven hardening layer thickness due to clamping misalignment. Simultaneously, the welding collaborative robot is equipped with force control sensors that automatically identify minute deviations between the workpiece and the fixture, compensating for welding path errors in real time to further guarantee the consistency of the hardened layer.
Program reuse: Parameter locking, batch copying for optimal results
For different sheet metal (4mm/6mm), the robot can preset and store the optimal program for welding hardening parameters (such as the diameter of the circular oscillation, the flat welding speed, the current-voltage curve, and the heat input). During multi-batch production, there is no need to readjust the process parameters; the corresponding program can be directly called. After the first piece of each batch is welded and hardened, the system automatically records data such as the hardened layer thickness and hardness. Subsequent workpieces only require parameter fine-tuning within ±5% to ensure that the batch hardened layer thickness deviation is ≤±0.2mm, the surface flatness is consistent, and the performance parameter fluctuation is ≤5%.
