31 results about "Shielded metal arc welding" patented technology

Provided are a gas-shielded metal arc welded joint of high-Mn steel, which is simple, has high strength and excellent extremely low-temperature toughness, and a method for producing the same. A gas-shielded metal arc-welded joint in which a welding metal is formed from a steel material of a high-Mn-content austenitic steel containing, in mass%, 18.0-30.0% of Mn using a shielding gas and a solid welding wire, the welding metal having a chemical composition containing, in mass%, 0.15-0.80% of C, 0.10-1.00% of Si, 17.0-30.0% of Mn, 0.030% or less of P, 0.030% or less of S, 0.001-0.100% of Al, 0.4-5.5% of Cr, 0.01-3.50% of Mo, 0.01-10.00% of Ni, and 0.0200-0.1500% of N, with the remainder being Fe and unavoidable impurities. Methods of making a gas shielded metal arc welded joint by incorporating a given concentration of nitrogen in a shielding gas, or increasing the N content of a solid wire.

The invention relates to the technical field of welding processes, in particular to a welding process method for optimizing martensitic stainless steel welding three-zone hardness, which comprises the following steps: welding by adopting gas metal arc welding, and controlling heat input to slow down the cooling rate; dual tempering heat treatment is carried out after welding, specifically, the first tempering temperature is 650-700 DEG C, and after first tempering, standing is carried out for a preset time length, and cooling is carried out to the room temperature; tempering for the second time at the temperature of 580-620 DEG C; wherein the base material is ultra-low carbon martensitic stainless steel, and the welding material is a nickel-molybdenum alloy welding wire matched with the base material. According to the method, gas metal arc welding is adopted for welding, and heat input is controlled to slow down the cooling rate; double tempering heat treatment is carried out after welding, the hardness of a weld zone, a fusion zone and a heat affected zone is eventually homogenized, and synergistic improvement of hardness homogenization and corrosion resistance is achieved.

The invention discloses a martensite heat-resistant steel G115 large-diameter thick-wall pipe welding and heat treatment process which comprises the following steps: step 1, performing groove processing on a to-be-welded position of a pipeline, and cleaning and preheating the to-be-welded position of the pipeline; 2, in the welding process, pulse argon arc welding is adopted for the root of the groove, flux-cored wire gas shielded welding is adopted for filling layer welding, low-hydrogen type shielded metal arc welding is adopted for capping layer welding, when filling and capping welding are conducted, segmented symmetrical synchronous welding is adopted for the welding sequence, the groove is divided into even number segments in the circumferential direction, and the number of the segments is equal to the number of the segments; two welders are used for synchronously welding at symmetrical positions; thirdly, after welding is completed, the welding position is subjected to slow cooling, high-temperature tempering and segmented cooling in sequence; through the design of dynamic heat input adjustment, segmented protection, precise temperature control heat treatment and the like, the cold crack risk is reduced, heat affected zone grain coarsening is restrained, residual stress is eliminated, and the mechanical property and service stability of a welded joint are improved.

An example welding power supply includes: power conversion circuitry configured to convert supply power to welding current and to output the welding current to at least one of a shielded metal arc welding (SMAW) electrode, a gas tungsten arc welding (GTAW) electrode, or a gouging torch; a voltage sense circuit configured to measure an output voltage of the power conversion circuitry; and control circuitry configured to: determine a droop slope based on an arc control parameter; determine a reference voltage corresponding to an amperage parameter; set a target current by adjusting the amperage parameter based on the droop slope and based on a difference between the output voltage and the reference voltage; and control the power conversion circuitry using a current-controlled control loop based on the target current.

The application discloses a method for assembling and welding a plug-in pipe with a thick-wall shell, which comprises the following steps: S1, cutting the thick-wall shell to obtain an opening and a bevel; S2, welding a backing plate under the inner surface of the thick-wall shell and at the edge of the opening through spot welding; S3, welding four clamping blocks on the outer wall of the plug-in pipe through spot welding, then vertically placing the plug-in pipe with the four clamping blocks on the backing plate in the opening, so that the longitudinal axis of the plug-in pipe overlaps with the longitudinal axis of the opening; S4, welding a right-angle weld close to the root of the plug-in pipe through shielded metal arc welding, then polishing the welding points of the clamping blocks and the plug-in pipe by using a grinder and removing the clamping blocks; and S5, welding in the bevel to weld the plug-in pipe with the thick-wall shell together, and after the welding is completed, removing the backing plate from the inner surface of the thick-wall shell through carbon arc gouging. The method improves the opening, assembling and welding efficiency, and guarantees the welding quality.

A shielded metal arc welding system includes a stick electrode holder, a stick electrode clamped by the holder, and a welding power supply operatively connected to the holder and configured to supply a welding current to the electrode through the holder. The power supply includes a memory storing both of a short circuit threshold voltage level and an arcing threshold voltage level. A welding voltage level is detected during an initial shorting of the electrode to a workpiece for commencing a welding operation. Both of the short circuit threshold voltage level and the arcing threshold voltage level are adjusted based on the detected welding voltage level. A short circuit clearing routine is activated when the welding voltage level is equal to or less than the adjusted short circuit threshold voltage level, and deactivated when the welding voltage level is equal to or greater than the adjusted arcing threshold voltage level.

The invention relates to the technical field of welding automation, in particular to automatic welding equipment and method.The automatic welding equipment comprises a base, a walking mechanism, a visual recognition module, a welding execution unit, a welding unit and a control unit, the walking mechanism adopts Mecanum wheels with the wheel faces made of flexible magnetic attraction materials, so that the walking mechanism has the omni-directional moving capacity and the high adhesion capacity; the visual recognition module is used for weld joint positioning and real-time molten pool monitoring, the welding execution unit comprises a multi-degree-of-freedom mechanical arm and a clamping assembly and can achieve all-position posture adjustment of a welding gun, the welding unit can be configured to be shielded metal arc welding or flux-cored gas arc welding, and the control unit controls the welding unit to conduct welding on the basis of molten pool characteristics fed back visually. Compared with a preset model, parameters such as the welding current, the voltage, the walking speed and the welding gun angle are dynamically adjusted in a closed-loop mode, intelligent self-adaptive control over the welding process is achieved, the welding quality stability and the operation adaptability are improved, and manual dependence is reduced.

The utility model belongs to the technical field of pressure vessel equipment manufacturing, and particularly relates to a gas metal arc welding semi-automatic device for equipment surfacing, which is characterized in that a vertical rod is fixed on a movable bottom plate vehicle, and one end of a horizontal rod is connected with the vertical rod through a fixed jacketed pipe; the horizontal rod has the freedom degree of vertical lifting and horizontal translation relative to the vertical rod, the other end of the horizontal rod is connected with the supporting pipe through the hinge type jacketed pipe, and the supporting pipe has the freedom degree of horizontal translation and pitching swing relative to the horizontal rod. One end of the supporting pipe is connected with a shielding gas source, the other end of the supporting pipe is closed, a shielding gas hood and a fixing clamp are fixed to the supporting pipe, and a gas shield welding gun can be installed on the fixing clamp in a relative movement mode. And protective gas enters from the supporting pipe and then is conveyed to the protective gas hood. The device can replace the operation that a welding worker holds a welding gun by hand, the manual welding time is shortened, the welding efficiency is improved, and the labor intensity of the welding worker is reduced.

The present invention discloses a welding method for a bimetallic composite pipe used in an acidic environment, which relates to the technical field of pipeline welding and specifically includes the following steps: (1) machining a stepped notch; (2) preparing a cladding powder; (3) cleaning and preheating the composite pipe; (4) laser cladding surfacing; (5) groove design and machining; (6) groove cleaning and preheating; (7) adding an isolation layer to the groove; (8) groove cleaning and assembly; (9) welding the base layer filling; (10) welding the base layer covering. The present invention divides the welding of the composite pipe into two parts: pre-welding treatment in the factory and post-welding treatment on site. Among them, the pre-welding treatment in the factory uses advanced equipment and technologies such as laser cladding for groove pretreatment, which facilitates subsequent post-welding treatment of the composite pipe directly on site using mature technologies such as tungsten inert gas welding and shielded metal arc welding, saving the process cost of on-site welding and improving the welding quality and efficiency.

This invention proposes a high-efficiency welding method for closely spaced pipes, belonging to the field of welding technology. It solves the problems in the industry where manual shielded metal arc welding (SMAW) is mainly used for fillet welds of closely spaced pipe joints. This method results in high labor intensity for welding operators, low production efficiency, and weld quality that is greatly affected by the operator, making it difficult to guarantee weld quality. This invention uses solid carbon dioxide gas shielded welding wire; employs a deep-penetration, low-spatter pulsed power supply; and determines the welding sequence as a left-hand welding method. Using solid welding wire for gas shielded welding of pipe joints improves production efficiency and reduces production costs. Compared with the commonly used SMAW method, solid welding wire reduces fume generation, purifies the operating environment, and improves the company's environmental protection level.

The utility model relates to the technical field of automobile parts, in particular to a multipurpose tail lamp support which comprises a tail lamp support body, the tail lamp support body is of an L-shaped structure, a first welding flange and a second welding flange are arranged at the upper end of the tail lamp support body, a first mounting hole is formed in the first welding flange, and a second mounting hole is formed in the second welding flange. And a second mounting hole is formed in the second welding flange. Under the condition that the multipurpose tail lamp support is universal for cargo compartments and breast board vehicle models, the tail lamp support can be welded to keep the same color as a vehicle body and can also be in threaded connection with black paint pieces, and the problem of poor corrosion resistance of carbon dioxide protection welding seam repair paint is solved. According to the multipurpose tail lamp support, an installation structure is additionally arranged on the tail lamp support, the structural stability of the tail lamp support is guaranteed, welding and screwing realizability is achieved, universality is high, the installation strength of black paint parts used for the tail lamp support of the composite board cargo compartment type is improved, paint spraying treatment at the connecting weld joint of carbon dioxide protection welding is avoided, and the corrosion resistance is improved.

The invention relates to a narrow-gap hot wire TIG (Tungsten Inert Gas)-welding rod hybrid welding method for high-strength wear-resistant steel, which is characterized in that a U-shaped groove is designed, a truncated edge of 2-3mm is reserved at the bottom, a welding mode and a welding process of combining an advanced narrow-gap hot wire TIG (Tungsten Inert Gas) welding method with traditional manual shielded metal arc welding are adopted, and welding seam backing welding and filling welding adopt narrow-gap hot wire TIG welding; the method has the beneficial effects that efficient welding of the thick-specification wear-resistant steel and the quality and performance of a welding joint are guaranteed, meanwhile, the wear-resistant steel welding seam with multiple excellent performance such as toughness, corrosion resistance and friction and wear resistance of the welding seam is achieved, the welding workload is small, the welding seam effect is good, and the welding quality is high. And a welding technical support is provided for popularization and application of the high-strength wear-resistant steel.

An example welding power supply includes: power conversion circuitry configured to convert supply power to welding current and to output the welding current to at least one of a shielded metal arc welding (SMAW) electrode or a gouging torch; a voltage sense circuit configured to measure an output voltage of the power conversion circuitry; and control circuitry configured to: control the power conversion circuitry using a current-controlled control loop based on a target current; while the output voltage is above a lower voltage limit, control the target current based on a difference between a reference voltage and the output voltage; and in response to detecting that the output voltage has decreased below the lower voltage limit, control a welding current output by the power conversion circuitry based on a first exponential relationship.

The invention belongs to the technical field of primary helium fans, and particularly relates to a primary helium fan impeller welding method. The impeller welding method comprises the following steps that an impeller disc and a lower blade are integrally formed, an impeller cover and an upper blade are integrally formed, and grooves are machined in the two sides, close to an interface, of the upper blade and the two sides, close to the interface, of the lower blade; any section of the groove is provided with a large groove on the first surface welding side and a small groove on the back gouging side; in the streamline direction of the blade, the two sides of the blade are each of a crossed structure with a large groove and a small groove; a lengthened and slender welding torch is adopted, and welding is conducted on the groove of the blade through gas metal arc welding or tungsten inert gas arc welding; a vacuum furnace is adopted for heating during welding, and inert gas is adopted for cooling after welding. According to the welding method for the main helium fan impeller, welding deformation of a thin plate is controlled, the welding quality is guaranteed in a long, narrow and twisted runner, and the effect that the surface of the main impeller runner is not treated any more after heat treatment is achieved.

The invention provides a narrow-gap hot wire TIG-plasma spray welding hybrid welding method for high-strength wear-resistant steel. The narrow-gap hot wire TIG-plasma spray welding hybrid welding method specifically comprises the following steps that S1, a semi-U-shaped groove is machined in the bottom of one side of a to-be-welded steel plate; s2, a narrow-gap hot wire TIG welding method is adopted, backing welding and filling welding are sequentially conducted on a welding seam, the welding current of a used hot wire TIG welding gun ranges from 100 A to 180 A, the welding voltage ranges from 12 V to 16 V, and the welding speed ranges from 100 mm / min to 150 mm / min; s3, shielded metal arc welding is adopted for cosmetic welding to prepare a weld joint surface corrosion-resistant layer, the welding current of shielded metal arc welding is 70-90 A, the welding voltage is 14-16 V, and the welding speed is 100-120 mm / min; s4, plasma spray welding is adopted for cosmetic welding to prepare a weld joint surface wear-resistant layer, and the welding current of plasma spray welding is 100-110 A; and S5, the surface of the welded joint is covered with heat preservation cotton till the welded joint is cooled to the room temperature. According to the method, efficient welding of the thick-specification wear-resistant steel and the quality and performance of a welding joint are guaranteed.

The application discloses a high-strength corrosion-resistant welded bridge production process and relates to the field of welded bridge production, which comprises the following steps: center pipe forming, flange assembly welding, accessory welding, end machining, shot blasting and aging treatment, surface spraying and the like. In the flange assembly welding step, the heated flange is sleeved into the center pipe end in an interference fit and is fixed by spot welding, the welding area is preheated, and then the outer welding seam is welded by synchronously feeding alloy powder into the molten pool by using the shielded metal arc welding, the inner welding seam is welded in the same way after cooling, heating and furnace cooling, and the whole workpiece is heated and stepwise cooled after welding; in the surface spraying step, the zinc-aluminum coating is sprayed on the surface of the workpiece after plasma cleaning by using the arc spraying process, the workpiece is sprayed with the penetration type epoxy sealing paint within a limited time while the workpiece is still warm, and then the epoxy primer and the polyester topcoat are coated in sequence. The application can significantly improve the comprehensive performance of the welding seam and the dimension precision of the component, and simultaneously improves the corrosion resistance of the welded bridge.

The invention discloses ultrasonic vibration assisted automobile aluminum radiator welding equipment and a welding method. The welding equipment comprises a consumable electrode gas shielded welding system, an ultrasonic vibration system, shielding gas and a welding working platform. The welding method mainly comprises the following steps that the aluminum radiator fins are assembled to the welding platform; welding process parameters, ultrasonic vibration process parameters and welding tracks are set respectively; opening the shielding gas, and performing ultrasonic vibration to assist the welding of the aluminum radiator for the automobile. The problem that electric arcs are unstable in the welding process of the aluminum radiator for the automobile is remarkably solved, and it is guaranteed that weld joints are well formed; the ultrasonic vibration platform can restrain the pore defect in the aluminum alloy welding seam, fine grain strengthening of the welding seam is achieved, the mechanical property of the welding seam is further improved, and finally a connector with the welding seam strength remarkably higher than the base metal strength is obtained.

The invention discloses a 7Ni steel back-gouging-free welding method which comprises the following steps: carrying out spot welding assembly on a 7Ni steel workpiece to be welded, carrying out backing welding on the inner root part of a front groove by adopting argon tungsten-arc welding, then carrying out shielded metal arc welding filling, then carrying out shielded metal arc welding or submerged-arc welding for capping, and not carrying out back gouging in a back groove, shielded metal arc welding is directly adopted for filling, and then shielded metal arc welding or submerged arc welding is adopted for capping. According to the 7Ni steel back-gouging-free welding method, the groove form and size are designed according to different thicknesses, argon tungsten-arc welding is adopted for backing welding, single-face welding and double-face forming are carried out, a full-penetration-welding root welding seam is formed, carbon arc gouging back gouging is replaced, the front and back grooves are filled with shielded metal arc welding, shielded metal arc welding or submerged-arc welding is adopted for capping, and the 7Ni steel back-gouging-free welding method is achieved. And the influence of carbon arc gouging on the performance of 7Ni steel can be effectively avoided, the working environment can be improved, the production efficiency can be improved, and the welding quality can be guaranteed.

The application provides an abnormality detection method and device for shielded metal arc welding. The method comprises the following steps: after shielded metal arc welding is started in a constant current mode, a first voltage and a first current are acquired in real time; an arc voltage is determined based on the first voltage, the first current and a first resistance obtained in advance; an actual arc resistance is determined based on the first current and the arc voltage; and an abnormality detection process is performed on the shielded metal arc welding based on the actual arc resistance and a preset standard arc resistance. According to the method, whether the welding is abnormal can be determined by detecting the change of the arc resistance, the abnormality detection process can be performed in time when the shielded metal arc welding is abnormal, the occurrence of welding defects can be effectively avoided, the intelligentization of the shielded metal arc welding is realized, and the welding efficiency is improved.

The present application belongs to the technical field of steel material and steel material welding, and proposes a gas shielded welding method for a martensitic bulletproof steel with a hardness of 600HBW. The method adopts a shielded metal arc welding method, a direct current reverse polarity power supply, and a rich argon mixed protective gas. According to the low strength matching principle, a solid welding wire is selected. The same plate thickness combination butt joint is continuously welded in a multi-layer and multi-pass manner. The preheating temperature of the steel plate is 100-150 DEG C, the welding line energy is controlled at 10-15 KJ / cm, and the welding joint is slowly cooled after welding by using asbestos. The present application ensures that the welding joint meets the shaping and toughness requirements, has high yield strength and tensile strength, the yield strength of the welding joint is greater than 1300 MPa, and meets the bulletproof performance requirements after welding. For the low alloy ultra-high strength martensitic bulletproof steel with a hardness level of 580-640HBW, the welding joint and the base material do not have cracking and other problems after welding.

In gas shielded arc welding, the goal is to enable stable arc starting regardless of the welding method. [Solution] In an arc start control method for gas shielded metal arc welding using welding wire or filler wire, the method includes at least a retract control period in which retract control is performed from the start of welding until the transition to a steady welding period; a start base period in which, after the retract control, the feed speed is alternately switched between a forward feed period and a reverse feed period, and the feed control method is changed to one cycle in which the forward feed period and the reverse feed period are repeated, and the wire is moved to a predetermined reference value related to the tip position of the welding wire or filler wire; and a start initial condition period in which, after the start base period, predetermined welding conditions are maintained for a predetermined period in the feed control method.

To provide a TKY joint high-strength high-toughness corrosion-resistant welding method for a deep water jacket.SOLUTION: A TKY joint high-strength high-toughness corrosion-resistant welding method for a deep water jacket includes preheating a T / K / Y joint at a predetermined temperature according to wall thickness of a base material, setting different welding parameters to different welding processes, performing rooting weld on the T / K / Y joint preheated by a coated arc welding process, then performing filling weld by a gas shield metal arc welding process, and finally performing capping weld by a gas shield metal arc welding process, wherein in the rooting weld, a corresponding welding rod is used, the performing capping weld selects a welding wire according to a low-strength principle, the filling weld selects a welding wire according to an equal-strength principle, and diffusible hydrogen contents of both an arbitrary welding rod and an arbitrary welding wire are equal to or less than a predetermined diffusible hydrogen content.SELECTED DRAWING: Figure 1

The application provides a welding method for improving the cold bending performance of a Q1400 steel welded joint, the welding method comprising the following steps: S10: providing a steel plate with a thickness of δ mm; S20: using shielded metal arc welding to perform backing welding on a bevel of the steel plate to form a backing layer, wherein E 打底 ≥ δ + 3 kJ / cm; S30: using shielded metal arc welding to perform filling welding on the bevel of the steel plate on which the backing layer is formed to form a filling layer, wherein E 填充 satisfies: E 填充 ≤ δ + 2 kJ / cm; S40: using shielded metal arc welding to perform covering welding on the bevel of the steel plate on which the filling layer is formed to form a covering layer, so that a welded joint composed of the backing layer, the filling layer and the covering layer is obtained; wherein E 盖面 ≥ δ + 3 kJ / cm. By using the welding method to weld Q1400 steel with different thicknesses, the obtained welded joint has good cold bending performance and high strength.

The disclosed technology generally relates to welding technologies and more particularly to electrodes for shielded metal arc welding. In one aspect the electrode includes an electrode core having an electrode core tip and a coating formed around the electrode core. The electrode core tip comprises an end surface, a tapered surface, and one or more surface features formed on the tapered surface. The surface area of the electrode core tip is greater than the surface area of a reference electrode core tip that is the same as the electrode core tip except for the presence of the one or more surface features. The coating is adhered to the tapered surface and at least partially covers each of the one or more surface features.

This invention discloses a welding process for connecting a gray cast iron interface flange and a low-carbon steel transition flange. By creating a bevel on one side of the gray cast iron interface flange, and using a combination of manual argon arc welding and shielded metal arc welding with φ3.2mm Z116 welding rods and φ3.2mm and φ4.0mm E5015 welding rods, an optimized welding process is employed to sequentially complete the welding of the transition layer, the root pass, the filler layer, and the capping layer. This effectively solves the production problems of leakage and the inability to replace parts in the bolted connection between the gray cast iron interface flange and the low-carbon steel transition flange of the blast furnace top residual pressure energy recovery power equipment reducer box. The process not only provides stable welding quality and high work efficiency, but also ensures safety, ease of operation, and low maintenance costs, effectively meeting the actual needs of the site and reducing operation and maintenance costs.

The application provides an automatic welding device for gas shielded welding, comprising: a workpiece, at least comprising a first side plate; a welding gun device, a first end of the welding gun device penetrating the first side plate and extending to the inside of the workpiece, the first end of the welding gun device being provided with an image acquisition device for acquiring image information in the workpiece, and a second end of the welding gun device being connected with a driving motor; a sliding displacement mechanism, comprising a sliding block fixedly connected with the workpiece and a sliding channel for the sliding block to slide thereon; a support frame, the support frame being fixedly connected with the first side plate and being used for supporting the welding gun device; and a fixing device provided on the support frame and used for fixing the welding gun device. The welding gun device provided by the application realizes accurate control and automatic operation of the welding process, and improves the welding efficiency and quality. The application provides a flexible welding gun fixing mode, which allows accurate adjustment of the height of the welding gun.

This invention discloses a gas shielded metal arc welding (GSMA) narrow-gap welding torch, comprising a conductive structure, a nozzle structure, and a gas support structure. The conductive structure includes a conductive nozzle with a wire feeding channel. The nozzle structure, made of high-temperature resistant insulating material, is fitted outside the conductive structure and includes a first nozzle section and a second nozzle section connected to the first nozzle section, the second nozzle section being configured as a flat structure. The gas support structure includes at least one anti-collision post, which is arranged laterally to the second nozzle section along its length. A second gas supply channel for delivering shielding gas is provided axially within the anti-collision post, the output direction of the second gas supply channel being consistent with that of the first gas supply channel. This GSMA narrow-gap welding torch is suitable for narrow-gap welding of thick materials, and it features high reliability, high safety, and good stability, greatly improving welding quality and efficiency.

In gas-shielded arc welding, stable arcing can be carried out in any welding method. The arcing control method in gas-shielded metal arc welding using a welding wire or a filler wire comprises at least: a retraction control period in which retraction control is performed from the start of welding to the transition to a stable welding period; a reference period is activated, and after the retraction control, the feed control method is changed to a feed control method in which the feed speed is alternately switched between a forward feed period and a reverse feed period and the forward feed period and the reverse feed period are repeated as one cycle. Transitioning to a predetermined reference value related to the tip position of the welding wire or filler wire; and a start-up initial condition period in which, after the start-up reference period, under a predetermined welding condition, the feed control method is maintained for a predetermined period.

The disclosed technology generally relates to welding technologies and more particularly to electrodes for shielded metal arc welding. In one aspect, a welding electrode comprises an electrode core and a coating formed around the electrode core. The electrode core has a centerline axis that extends along its length and comprises an electrode core body and an electrode core tip. The electrode core body has a circular cross-section having a radius. The electrode core tip has two or more recessed portions and two or more unrecessed portions. The two or more recessed portions extend along a length of the electrode core tip and a radial distance between the centerline axis and a surface of one of the recessed portions is less than a length of the radius. The coating comprises a flux material.

Provided are a coated electrode, a welded metal, a method of electrode arc welding, and a method of manufacturing a welded joint. A coated electrode for high-tension steel, which can obtain a welded portion that can maintain a target strength, has excellent low-temperature toughness, and has suppressed hot cracking, not only in the As-welded state but also under a wide range of PWHT conditions. The coated electrode contains CO2: 16% to 27%, F: 4% to 10%, Si: 3% to 11%, Ni: 7.5% to 13.3%, Fe: 1% to 11%, Mo: 0.3% to 1.0%, Cr: 0.15% to 1.2%, Mg: 1.5% to 4.5%, and Mn: 1.5% to 4.0%, and when the contents of Ni, Mn, and Si in the coating are represented by [Ni], [Mn], and [Si], respectively, the value calculated from [Ni] / ([Si]+[Mn]) is 0.85 to 1.45.