mijobooks Chapter 92 Overhead Welding
Chapter 92 Overhead Welding
In the welding competition room, only the last overhead welding test was left to be conducted.
Ding Haisheng stood next to the water tap at the entrance of the competition room, tucked his mask under his arm, and splashed a handful of cold water on his face.
Water dripped from his chin onto the collar of his work clothes, leaving a small wet patch. He wiped it with his sleeve.
The vertical and horizontal welding tests were already completed, and the appearance score for the weld was given on the spot without him looking at the scoring sheet.
As Lao Fang once said, once the welding is done, it's done. Staring at the evaluation form won't change anything, so it's better to just finish welding the rest.
He put on the mask; the marks from yesterday's wiping were still on the goggles, and the sunlight in the yard looked a bit bluish through them.
He walked into the competition room and stood at his workstation.
The judge turned a page of the scoring sheet. Two contestants from other counties were squatting at their workstations, organizing their welding rods. One of them looked up at him, then looked down again.
The last item is overhead welding of a 12mm thick steel plate, with single-sided welding and double-sided forming, and a weld length of 300mm.
It's exactly the same as what I practiced at the service station.
He clipped the welding rod into the welding clamp, but didn't immediately light the arc.
First, run the welding pliers around the position twice to get a feel for the wrist's movement.
There was no sea breeze in the competition room, the doors and windows were all closed, and the fluorescent lights overhead were humming.
It's much easier to weld indoors when there's no wind than outdoors, so he practiced outdoor overhead welding for almost a year.
At the entrance of the new workshop of the service station, the wind blew in from the north, making the arc light flicker, and the molten iron dripping down never looked away.
The welding clamp touched the spot, and an arc of light flashed.
Molten iron flowed down from the tip of the welding rod, melting the dead iron at the edge of the steel plate bevel into a small pool of bright red liquid.
He moved his wrist very slowly, drawing tiny circles with the welding rod in the molten pool, filling the pool with molten iron circle by circle.
For the first root pass, molten iron flows upwards and is pulled downwards by gravity, causing slight ripples on the surface of the molten pool.
He pressed the welding rod down slightly to control the temperature of the molten pool.
The parameters written on the paper went through his mind again and again.
The current for the root pass is 95 amps, for the fill pass it is 110 amps, and for the cover pass it is 105 amps.
When he practiced at the service station, he took notes on hundreds of sets of data in a notebook. He noted the results after each set of data, indicating which set had good back-side formation, which set had porosity, and which set had excessive weld reinforcement.
Ding Haifeng helped him organize those data, measured the weld width and excess height with a micrometer, and wrote them down on a draft paper. The writing was dense, and the unit was noted after each data point.
The first pass is the root pass welding and the arc is closed.
He used a welding hammer to knock off the welding slag, revealing the weld underneath.
The fish scale pattern is even and there are no jagged edges.
He flipped the steel plate over to look at the back, and saw that the weld had penetrated through, forming a neat, straight line.
Just like the weld he practiced hundreds of times at the service station.
He pushed up his mask and used cotton gauze to wipe the welding slag off the goggles.
The judge walked over, bent down to look at the weld, then looked at the depth of penetration on the back, made a few notes in his notebook, and walked back to the judges' table without saying a word.
The second filler weld.
He changed the welding rod and adjusted the current to 110.
As the arc of light flashed again, a very soft sigh came from the other end of the arena.
The contestant at station number three had poor back weld formation and insufficient penetration, so the judges asked him to re-weld it.
The athlete took off his goggles, wiped the sweat from his forehead, and rubbed his palms on his pants.
Ding Haisheng didn't look in that direction.
When he was welding the filler weld, his wrist was slightly faster than when he was welding the root weld. The molten iron filled the gap between the first weld and the bevel, and the surface of the molten pool was smooth.
A small section of the burn scars on his wrist peeked out between his gloves and cuffs; the fresh red marks hadn't faded yet, while the old scars had already turned white.
He recalled that the night before last, after the mock competition ended, Lao Fang, with a cigarette in his mouth, squatted at the entrance of the new workshop and called him over.
"Your welding skills are good enough." Old Fang took the cigarette out of his mouth and flicked off the ash. "But the competition isn't a service station. The judges won't look at how many times you've practiced. They'll only look at this one time. If this one time is good, it's good; if it's not, it's not."
"What if this time it's not stable?" Ding Haisheng was squatting by the door frame, transferring the welding rod box from his left hand to his right.
"The instability is your fault for welding it." Old Fang put the cigarette back in his mouth, stood up, and patted the ash off his knees. "That's the life of a craftsman. Practice a thousand times, take the test once. Once you accept it, you won't be nervous anymore."
Fill weld and end the arc.
He knocked off the welding slag and touched the edge of the weld with his finger. It was still hot, so hot that his fingertip recoiled.
The transition between the weld and the root pass is smooth, with no undercut.
He glanced at the judges' table; the judges were flipping through the score sheets, and the scores of the two contestants next to him had already been displayed, but he couldn't see them clearly.
The third cover weld.
He clipped the last welding rod into the welding tongs and adjusted the current to 105. When he pressed the welding tongs down, he wasn't thinking about anything.
The wrist movement was more stable than the previous two, and the welding rod moved in circles in the molten pool at a uniform speed. As the molten iron was poured on, a fine fish-scale pattern slowly formed on the surface of the weld.
He took a breath when the welding rod was halfway through, but didn't stop.
The welding rod moves at a constant speed from left to right, and the 300-millimeter weld seam comes to an end. He gently withdraws the arc, and the molten pool slowly solidifies, leaving a shallow crater.
He took off his mask and used a welding hammer to knock off the welding slag from the cover.
After tapping it twice, the welding slag fell off in one piece, revealing the weld underneath.
The fish-scale pattern is evenly distributed from head to tail, with no undercut or porosity. The weld reinforcement was estimated by the naked eye to be about one and a half millimeters, which is within the standard range.
He flipped the steel plate over to look at the other side.
The lines on the back, which are deeply fused through, are neat and orderly, without any breaks or indentations.
It was exactly the same as the weld he made at the service station, the one that Lao Fang had looked at three times without finding any fault.
The judge walked over, bent down to look at the weld on the front, and then looked at the penetration depth on the back.
He studied it for a long time, longer than he had studied the previous two questions, then straightened up and took a pen to write a few notes in his notebook.
The two contestants from other counties next to him had finished welding and were also waiting for their scores. One of them saw the depth of Ding Haisheng's weld on the back, paused for a moment, leaned over to take a look, and then went back.
Ding Haisheng hung the welding clamps on the worktable, put away the welding rod box, and stood in front of his workstation to wait.
He didn't ask about the score or look at the evaluation sheet; he simply wiped the goggles with cotton gauze again.
The judge called over another experienced worker from outside the competition room. The two of them squatted in front of the steel plate, pointed to the depth of the melt on the back, and whispered something to each other.
Ding Haisheng didn't hear clearly.
He hung the mask on the tool bag, pinched the strap of the tool bag with his fingers, and a small patch of the canvas on the strap was dampened by his sweaty hands.
The judge stood up, wrote a score on his notebook, and glanced up at him.
"From Moon Island. Who did you learn welding from?"
"Master Fang Desheng."
"Good technique." The judge turned to the previous page of the score sheet, looked at the scores for vertical and horizontal welding, and then closed the score sheet. "Weld appearance: 92; back surface formation: 90; overhead welding: 91."
Ding Haisheng's fingers were a little stiff when he took the evaluation sheet.
That score wasn't something he achieved by practicing alone at the service station; it was a score he earned together with Lao Fang, Ding Haifeng, and everyone else who watched him squatting at the entrance of the service station, welding again and again.
He folded the score sheet and put it in his tool bag, then nodded to the judge.
"Thanks."
"You're welcome. You soldered it yourself."
Ding Haisheng walked out of the competition room.
The sunlight was already directly overhead, and the cement ground in the yard was bleached white by the sun.
Jiang Haiping leaned against a cement pillar against the west wall. The loquat leaf in his hand had been crushed at some point, and the broken leaves fell to his feet. He wiped them with the sole of his shoe.
He saw Ding Haisheng come out, but instead of asking about his score, he just glanced at the evaluation sheet in Ding Haisheng's hand.
"Ninety-one for overhead welding." Ding Haisheng handed him the score sheet.
Jiang Haiping took it and read it from beginning to end.
After reading it, he folded the rating sheet, handed it back, and nodded.
He glanced back into the competition room; the door to the welding competition room was already closed, and the judges were organizing the score sheets.
Ah Hai's voice came from the west wall, "I told you, I said he was fine with overhead welding."
Ah-Guang ran over from the entrance of the competition room, still clutching the ballpoint pen he used to draw circles to relieve stress.
Ding Haifeng also came over. He had been standing outside the old parts management room for most of the morning, watching Zhou Haisheng's competition and then watching the old parts judgments of three other contestants.
He walked up to Ding Haisheng, took the micrometer box out of his pocket, thought for a moment, and then put it back.
"Have a piece of sesame candy first." He nudged his brother with his elbow.
"OK."
Ah Hai had already stuffed the sesame candy into his hand.